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Meta Reality Labs published the MobileLLM-Pro technical report on November 10, 2025, describing a 1.08B-parameter language model built for phones and wearables. The model handles a context window of 128,000 tokens, four times what Gemma 3 1B and Qwen 3 0.6B accept. Quantising weights and embeddings to 4 bits takes the file from 2.2 GB in bf16 down to 590 MB for the CPU build and 720 MB for the accelerator build, which cannot share embedding weights.

Meta exported the model through ExecuTorch and measured it on a Samsung Galaxy S25 CPU with the XNNPACK backend and on a Samsung Galaxy S24 Hexagon Tensor Processor. On a 2,000-token prompt the paper reports 8.9 s of prefill on the CPU against 2.0 s on the Hexagon unit, and decode speeds of 33.6 tok/s and 31.6 tok/s while generating 1,000 tokens. At 8,000 tokens prefill climbs to 63.5 s on the CPU and 9.8 s on the Hexagon unit, decode falls to 19.7 and 22.8 tok/s, and the key-value cache grows from 14 MB to 40 MB.

The architecture puts 30 layers of width 1280 behind 20 attention heads and 4 key-value heads, and shares one weight matrix between the input embedding and the output head, which the authors say saves 260M parameters, about a quarter of the model. Three out of every four layers use local attention, comparing each token only against the 512 most recent ones, with a global layer every fourth one and at both ends. Meta’s model card credits that interleaving with cutting the key-value cache at 8,000 tokens from 117 MB to 40 MB and with 1.8 times lower prefill latency than global attention in every layer. Meta trained the model by distilling the logits of Llama 4 Scout under a KL divergence loss across three pretraining phases on roughly 1.64T tokens of open data, the second of them a step the authors call implicit positional distillation, which stretches the context window to 128k by having the teacher pass on the ability rather than feeding the student long documents.

Meta puts the base model 5.7 and 7.9 points above Gemma 3 1B and Llama 3.2 1B on average across the benchmarks its model card lists, and the paper’s table has it at 76.24 on BoolQ against 63.20 and 62.51, at 52.62 on ARC-Challenge against 38.40 and 38.28, and at 100% needle-in-a-haystack retrieval against 96.80 for Llama 3.2 1B. The instruction-tuned version scores 59.8 on HumanEval against 41.5 and 37.8, 44.8 on MMLU against Gemma’s 29.9 and Llama’s 49.3, and 62.0 on IFEval against Gemma’s 80.2. In Meta’s own human evaluation over 100 prompts per task, raters preferred Gemma 3 1B for summarisation 51 to 47 and for rewriting 49 to 45, while MobileLLM-Pro led on recall 47 to 30.

Meta released four checkpoints on Hugging Face, the base model, the instruction-tuned one, and two quantisation-ready base checkpoints produced by quantisation-aware training with self-distillation from the full-precision model. One uses 4-bit group-wise weights at group size 32 with 8-bit dynamic activations and an 8-bit key-value cache for CPU backends, the other 4-bit channel-wise weights for the Apple Neural Engine and Qualcomm’s Hexagon processor, which handle group-wise quantisation poorly or not at all. Needle-in-a-haystack retrieval holds at 96.44% and 98.67% against 100% at full precision. The weights sit behind a request form and carry the FAIR Noncommercial Research License.

Researchers at Zhejiang University, Zhejiang University of Technology and Hangzhou Dianzi University published Confidant in the ACM MobiCom 2025 proceedings on November 3, 2025, a day before the conference opened in Hong Kong. The framework fine-tunes a language model across several off-the-shelf devices instead of one, and the authors fine-tuned Phi2-2.7B on the Alpaca instruction dataset in 40.1 hours using three of them. Their write-up of that run names a Redmi K50 phone, a Core i7-13650HX laptop and a MacBook Pro with an M1 Pro, while the paper’s abstract and conclusion describe the same result as three mobile devices. The same trio fine-tuned BERT-Base in 2.2 hours.

Confidant cuts a model into consecutive slices, gives each device one slice, and passes activations from one device to the next, so no device ever holds the whole model. Batches flow through that chain as a pipeline, with each device starting a new batch while the devices behind it are still working on earlier ones. The device that holds the training data acts as coordinator and recalculates where the cuts fall during training, using each participant’s measured compute time, free memory and bandwidth, and it discards any split whose slice would not fit in a device’s memory. Inside a device, a second scheduler profiles the CPU and the GPU on varying numbers of attention heads and gives each processor as many heads as it can finish in roughly the same time, which is what the authors credit for running up to 1.94 times faster than a capacity-aware pipeline baseline they implemented themselves, and up to 3.82 times faster than the best single device, both on GPT-2 Medium.

Splitting the model is what brings the footprint per device down. The paper’s memory table puts fine-tuning BERT-Base at a batch size of 8 at 5.5 GB on a single Redmi K50, against a per-device average of 3.17 GB across three devices and 2.43 GB across four. Larger models leave no single-device figure to compare with, because a Redmi K50 fits only 1 of Phi2-2.7B’s 32 transformer blocks at a batch size of 4, and the per-device averages of 15.31 GB for Phi2-2.7B and 32.07 GB for LLaMA3-8B across three devices are carried by the two laptops rather than the phone. A separate table puts the memory PyTorch needs to fine-tune Phi2-2.7B at a batch size of 8 at 46.5 GB, next to the 8 GB to 12 GB of the four phones it lists.

The paper’s prose says Confidant almost does not cause any accuracy drop, while its own model performance table puts the three-device runs at a test loss of 0.66 on Phi2-2.7B and 3.55 on LLaMA3-8B, against 0.52 and 2.86 for fine-tuning the same models the conventional way on a single machine, where a lower loss is better. The four-device runs land at 0.76 and 2.85 on that same comparison, and BERT-Base token classification accuracy holds at 97.66% against 97.70%.

Keeping data on the device is the stated motivation. The authors write that training with Confidant does not require sharing raw data and that devices exchange only intermediate outputs and model gradients, which they present as the privacy argument for their two scenarios, a household assistant fine-tuned on family data during idle hours and a conference assistant fine-tuned on attendees’ phones. They also state that fine-tuning on a single cloud server would be faster and more straightforward, and that their aim is to use idle mobile hardware instead. The Android side is built on Alibaba’s MNN framework with laptops running PyTorch, about 10,900 lines of code in total, the paper is published under a Creative Commons Attribution 4.0 license, and the authors wrote that they planned to release the code in late 2025.

The PyTorch team released ExecuTorch 1.0 on October 22, 2025, the generally available version of its runtime for PyTorch models on phones, laptops and embedded devices. It takes a model straight from PyTorch without converting it to ONNX or TFLite and without rewriting it in another language, which the team says removes a common source of numerical mismatches and lost debug information. The beta arrived in October 2024.

Five backends moved from beta to production status. XNNPACK with Arm Kleidi covers CPU, Apple Core ML covers Apple silicon, the Qualcomm AI Engine delegate covers the Hexagon NPU, and Arm Ethos-U and Vulkan cover NPU and GPU. New backends arrived for Arm VGF, the NXP eIQ Neutron NPU, Samsung Exynos NPU and GPU, and Intel OpenVINO.

Meta says features built on ExecuTorch already run on Instagram, WhatsApp, Messenger and Facebook. Anuj Kumar, Director at Reality Labs, describes what it drives in Meta’s wearables, including the Ray-Ban Display glasses with EMG band.

Advanced AI features like speech recognition, motion sensing, and computer vision run on these devices by leveraging cutting-edge hardware.

Lysandre Debut, Chief Open-Source Officer at Hugging Face, says more than 80 percent of the most downloaded edge-friendly language models on Hugging Face run on ExecuTorch out of the box. The team validated coverage across object detection, depth, OCR, speech recognition and segmentation as well as text and multimodal models such as Voxtral for audio and Gemma 3 for image and text input. The main branch also allows embedding ExecuTorch into native C++ desktop applications.

Researchers at Georgia State University and Toyota InfoTech Labs published lm-Meter, a latency profiler that runs inside the inference engine on the phone and splits each generation into embedding, prefill, decode, softmax and sampling. Measuring the Pythia models on a Google Pixel 8 Pro, they report that scaling from 70M to 1.4B parameters raises prefill latency from 0.012 s to 1.9 s per input token, a 158x slowdown, while decode latency per output token grows from 0.015 s to 0.15 s, a 10x slowdown. The authors write that this inverts the server picture, where decode is usually the limiting phase for single-request inference.

Below the phase level the profiler times individual GPU kernels through OpenCL event timestamps, which give queue, submit, start and end times without access to the closed-source driver. Running a 4-bit quantised Gemma-2-2B-it on a Pixel 8 Pro, the authors report that fused matrix-multiplication kernels dominate a decode step and that the GPU sits idle for more than 21% of it, the second-largest contributor to the step, which they attribute to host-side data preparation and I/O stalls. The paged attention kernel that scans the growing key-value cache is the only one whose cost rises with position in the sequence, climbing from roughly 0.2 ms to about 0.8 ms per token over 250 decode steps, and idle time drops from about 21% to 12% when the model generates 256 tokens instead of 16.

Whether those measurements mean anything depends on what the profiler itself costs. lm-Meter sits in the MLC LLM runtime and TVM in about 3,500 lines of code and needs no host machine attached, and under the Powersave CPU governor, the most constrained setting they tested, the authors measure a throughput loss of 2.58% in prefill and 0.99% in decode. They put the same figures for MELTing Point, the on-device profiler they compare against, at 22% for prefill and more than 93% for decode. Checked against traces from Android GPU Inspector, they report end-to-end phase accuracy of at least 99.99% and mean kernel-level accuracy of 96.82% on the Pixel 8 Pro and 96.61% on a Pixel 7.

The code is on GitHub under the MIT license, with the MLC LLM path released for Android GPUs through OpenCL and support for llama.cpp, vLLM, iOS Metal and Nvidia Jetson listed as unfinished. The work was accepted to the ACM/IEEE Symposium on Edge Computing 2025 and funded by Toyota Motor North America. The measurements come from three phones, the Pixel 8 Pro, Pixel 7 and Pixel 6, and the authors state that other edge platforms such as Jetson boards and Intel NPUs may show different bottlenecks.

Meta released MobileLLM-R1 on September 12, 2025, a family of reasoning models at 140M, 360M and 950M parameters that write out a chain of intermediate steps before giving an answer instead of replying directly. Meta reports the 950M model scoring 74.0 on the MATH500 maths benchmark and 19.9 on LiveCodeBench v6, against 73.0 and 14.9 for Qwen3-0.6B. The technical report followed on September 29, 2025.

The three models saw 4.2T training tokens, which Meta puts at 11.7% of the 36T tokens behind Qwen3-0.6B. Pre-training ran in two phases of 2T tokens each, resampled from a curated pool of roughly 2T tokens of open datasets, followed by two mid-training phases of 100B tokens that distil from Llama-3.1-8B-Instruct as a teacher, then supervised fine-tuning on reasoning traces. Meta uses the result to argue that reasoning does not require the corpora above 10T tokens that recent models have been trained on.

For the post-trained models Meta’s table puts MobileLLM-R1-950M at 74.0 on MATH500, 67.5 on GSM8K, 15.5 on AIME 2024 and 19.9 on LiveCodeBench v6, where Qwen3-0.6B reaches 73.0, 79.2, 11.3 and 14.9 and DeepSeek-R1-Distill-Qwen-1.5B reaches 83.2, 77.3, 29.1 and 19.9. Among the models whose weights, data and recipe are all public, the same AIME figure compares with 0.6 for OLMo-2 1.48B and 0.3 for SmolLM2-1.7B. On code the 950M base model scores 46.3 on HumanEval against 30.5 for Qwen3-0.6B-Base, and the 140M base model reaches 15.9 where SmolLM2-135M scores 0.0.

Meta profiled the models through ExecuTorch on a Samsung Galaxy S22 with 8 GB of RAM, quantised to 4-bit weights with 8-bit dynamic activations. The 140M model generated 129.67 tok/s at a 1k context and 79.71 tok/s at 32k, the 950M model 31.05 tok/s at 1k before running out of memory at 16k, and Llama-3.2-1B 28.71 tok/s at 1k with the same memory failure. The architecture follows Meta’s earlier MobileLLM work and Llama 3.2, sharing one weight matrix between the input embedding and the output layer, and the post-trained models take a 32k context.

Meta released the weights on Hugging Face together with the training code, the data sources and the data mixing ratios on GitHub, under the FAIR Noncommercial Research License, which covers research, education and analysis but not commercial use. Access to the model repositories is gated behind a form.

Update, November 24, 2025. Meta released MobileLLM-R1.5 at the same three sizes, fine-tuned from the R1 models with one further round of on-policy distillation, where the student answers first and the teacher, here Llama-3.1-Nemotron-Nano-4B-v1.1, grades its own words back to it token by token. Meta reports the 950M version at 86.6 on MATH500, 82.6 on GSM8K, 39.9 on AIME 2024 and 29.1 on LiveCodeBench v6, up from 74.0, 67.5, 15.5 and 19.9 for MobileLLM-R1-950M, and says it beats DeepSeek-R1-Distill-Qwen-1.5B on every maths and coding benchmark it ran. At 360M Meta puts MATH500 at 63.4 against 28.4 and GSM8K at 52.8 against 24.5.

Apple announced the A19 Pro alongside the iPhone 17 Pro on September 9, 2025. Its 6-core GPU carries Neural Accelerators built into each core, which Apple says work together with the 16-core Neural Engine to power AI models, graphics and games. The company states that the chip enables running large local language models on the phone.

The A19 Pro also has a 6-core CPU that Apple calls the fastest in any smartphone, along with a larger cache and more memory than the A18 Pro. Combined with a vapor chamber cooling system, Apple puts sustained performance at up to 40 percent above the previous generation.

Researchers from Peking University and BUPT report up to 4.5 times faster end-to-end inference on a Xiaomi 14 with a Snapdragon 8 Gen 3, and 3.5 times faster on average for the attention kernel alone, with a peak of 6.9 times. The baseline is the arrangement most on-device frameworks use today, float32 full attention running on the CPU or GPU while the rest of the model sits on the NPU. The authors measured Qwen2-0.5B, Qwen2-1.5B, PhoneLM-0.5B and PhoneLM-1.5B on summarisation and two mobile agent tasks, and gave their own system only one of the phone’s middle CPU cores. Against the native attention of llm.npu, which uses four CPU cores or the GPU, they report up to 3.0 times lower latency from that one core. The paper is due at MobiSys 2026.

The starting problem is that attention keeps falling back off the NPU. Attention multiplies three activation tensors together, and mobile NPUs compile a static graph that fixes one quantisation scale factor for a whole tensor, so the authors measure an average 18 percentage point accuracy drop when the operator runs in INT8 on the NPU. Their trade is to stop asking the NPU for the answer and ask it only for the ranking. The NPU computes the query-key scores in INT8 purely to find which tokens matter, which the authors report recovers over 99 percent of the positions a float run would pick, since picking the largest values needs relative magnitudes rather than exact ones. The CPU then computes real attention in float over roughly 20 percent of the tokens and throws the other 80 percent away, at an average accuracy cost of 0.4 percentage points against the float baseline. Each attention head gets its own sparsity ratio, fixed by an offline profiling run the paper puts at about five minutes on a single A100.

On a Redmi K60 Champion Edition with a Snapdragon 8 Gen 2 the authors read battery voltage and current from the kernel and report a single attention kernel at 1024 tokens dropping from 8.59 J to 1.12 J for PhoneLM-1.5B, a factor of 7.66. Speedups on that older phone are smaller, 2 times, 1.25 times and 1.22 times across the three datasets, which the authors attribute to its Hexagon V73 NPU against the V75 in the Xiaomi 14. The paper reports no memory footprint figures. It does report that end-to-end inference time on the Xiaomi 14 stayed between 14.5 and 15.5 seconds while the phone was also taking photos, playing video, playing music or running a shopping app, since the LLM work is not competing for the cores those apps use.

The authors state a prototype of more than 10,000 lines of C++ and Python, built on Qualcomm’s QNN and Hexagon SDK for the NPU side and integrated into llm.npu, which they call the only fully open-source framework running on NPUs. The paper names no repository and announces no artefact release, and the title calls the system ShadowNPU while the text throughout calls the module shadowAttn. The arXiv listing carries a CC BY 4.0 license. For a hands-on point of comparison on the same silicon family, a user test of llama.cpp’s Hexagon NPU backend on a Snapdragon 8 Gen 3 phone put generation at about the same speed as the chip’s CPU, without the heat.

Thirty researchers at Huawei Technologies published P/D-Device on August 12, 2025, a scheme that runs a single language model request across a cloud data centre and a phone at the same time instead of choosing one of them. The cloud reads the prompt and writes only the first few tokens, then the device carries the answer to the end. The authors measure average time to first token falling by at least 60 percent against running the whole request on the device, and cloud throughput rising by 1.6 to 15 times, 7.6 times on average, against letting the cloud generate a full 200-token answer.

The split follows from the two phases of inference wanting different hardware. Prefill, where the model reads the prompt before it writes anything, is compute-bound, and the authors report on-device time to first token climbing steeply with prompt length, into seconds or tens of seconds once prompts run to several thousand tokens. Decoding, where the model emits one token at a time, behaves differently, because a phone serves one user while a cloud instance serves a large batch, so the authors find the two roughly matched at tens of milliseconds per output token. Decoding is also what occupies a cloud instance for tens of seconds per request, so the scheme cuts the cloud off after a set number of tokens and hands the rest of the answer to the device.

The device displays the cloud’s first token the moment it arrives, so the wait the user actually perceives is the cloud’s prefill, which the authors put at hundreds of milliseconds. Behind that display the device runs its own prefill while a speed controller releases the next tokens from the cloud at a deliberately slowed pace, matched to human reading speed, until the device has caught up and generates the rest itself. During its prefill the cloud also scores the prompt using the attention weights it has already computed, picks the sentences that matter most, and returns the selection as a compressed mask so the device prefills a shorter prompt, with a quarter of the prompt kept by default.

What crosses the network is text, never model state. The device sends the prompt as raw text and the cloud returns the first token, the mask and a token budget, which the authors cap at hundreds of kilobytes for an 8k prompt, while the KVCache, the gigabyte-scale intermediate state that other cloud-device schemes ship back and forth, is too large to move in time and is never transferred at all. On the prompt text itself the authors state that the request goes out only under user and app authorisation and after sensitive information such as phone numbers and real names has been removed or substituted, and they cite Apple’s Private Cloud Compute as the class of guarantee they have in mind, without describing an implementation or measuring one. The archive’s post on Flower Intelligence covers the reverse arrangement, where the device runs first and the remote service stays off unless the app turns it on.

The prototype runs cloud inference on Huawei Ascend NPUs and device inference on Kirin SoCs, tested on a phone and a tablet, with every chip and model anonymised as Type 1, Type 2, Model 1 and Model 2 throughout the paper. On LongBench with the same model on both sides, the authors’ own table gives their refinement an average of 26.64 on single-document QA against 25.89 for the unrefined on-device baseline, and 26.83 against 22.96 on multi-document QA. The authors name the costs themselves, a quality score around 85 percent of cloud-only inference when the cloud runs the larger model, refinement adding one or two hundred milliseconds at an 8k prompt and several hundred under load, and the smoothed display running slightly above their own tolerable threshold of about a hundred milliseconds per token once prompts pass 8k. The paper, on arXiv under a CC BY 4.0 license, further states that connections were tested over Wi-Fi with an IP whitelist rather than LTE, that collaboration across different NPU types is still being explored, and that the device supports prompts of several thousand tokens against hundreds of thousands in the cloud.

Ten researchers at Beijing University of Posts and Telecommunications, Peng Cheng Laboratory, the University of Cambridge, Xiaomi, Helixon Research and Flower Labs collected 68 small language models between 100M and 5B parameters, released by 24 organisations between OPT in May 2022 and Llama 3.2 in September 2024, and measured both their accuracy and their cost on edge hardware. In Demystifying Small Language Models for Edge Deployment, presented at ACL 2025, Microsoft’s Phi-3 and Phi-3.5-mini sit highest on the capability chart at about 70 percent average accuracy over 10 reasoning and knowledge datasets, level with the Llama 3.1 line the authors draw for comparison. The runtime half of the study covers the 20 models that llama.cpp supports, quantised to 4-bit and run with a 50-token prompt and 50 generated tokens.

Parameter count predicts on-device latency poorly. The measurements put OpenELM-3B at 9.4 percent more parameters than Phi-2 but 9.9 percent faster to the first token, and Qwen1.5-0.5B at 25.4 percent more parameters than Qwen2-0.5B yet 31.9 percent faster to the first token and 11.8 percent faster per decoded token. Qwen1.5-1.8B carries 30.5 percent more parameters than Pythia-1.4B and still reaches the first token 18.5 percent sooner. The authors trace the gap to how a model spends its parameter budget, with Qwen2 sharing its input embedding and output layer and putting the saved weights into wider attention and feed-forward layers, which costs compute in the prefill stage.

Memory ran from 275 MB to 2456 MB across the 20 models, measured with llama.cpp on a Jetson Orin NX at a fixed 2048-token context. Vocabulary size moves that figure as much as parameter count does, and the paper reports Bloom-560M needing 492 MB of compute buffer for its 250,880-token vocabulary, 3.5 times what OpenELM-1.1B needs with 32,000 tokens. OpenELM-1.1B uses 23.8 percent less memory than Bloom-560M despite 32.3 percent more parameters, and OpenELM-3B 13.8 percent less than Gemma-2B despite 21.1 percent more, which the authors put down to the small vocabulary and to grouped-query attention, where several attention heads share one set of cached keys and values. Raising each model to its own maximum context window pushes Qwen2-0.5B past 6 GB, with compute buffer and KV cache making up 85 percent of the total for the Qwen2 models.

Quantisation paid off in decoding rather than in prefill. Testing five settings on Phi-1.5, the authors found Q4_K_M the strongest, roughly halving per-token decode latency against FP16, while at a 50-token prompt it cut the time to the first token by only 13 percent. Q6_K and Q3_K matched or exceeded FP16 on longer prompts, which the paper puts down to the alignment and padding their irregular bit widths force. The hardware gap was wider than the quantisation gap, with the Jetson’s GPU 40 times faster than the Meizu 18 Pro’s CPU at prefill but only 1.84 times faster at decode, and the Xiaomi 12S on a Snapdragon 8 Gen 1+ the fastest of the three phones, ahead of the Pixel 7 Pro and the Meizu on its Snapdragon 888.

The authors name two limits on their own work. They left math datasets out of the capability evaluation because of the gap between small models and larger ones on mathematical reasoning, and they confined the cost analysis to the 20 models llama.cpp supports so that the inference engine stayed constant, excluding every model it cannot load. The paper is free to read at the ACL Anthology under a Creative Commons Attribution 4.0 licence, and the same group had earlier measured 22 models from 0.5B to 7B on four Android phones, three of which reappear in this test bed. PalmBench adds power draw and surface temperature on comparable hardware, and Artificial Analysis has since reported quality, speed and memory together for 33 quantised models on one iPhone 17 Pro.

Apple posted its 2025 foundation models tech report to arXiv on July 17, 2025, giving the numbers behind the roughly 3-billion-parameter on-device model it shipped at WWDC25. The report’s Table 3 puts the price of compressing that model to 2 bits per weight at 3.4 points of MMLU, from 67.8 in 16 bits down to 64.4, with IFEval falling from 85.1 to 82.3.

Apple reaches 2 bits through quantisation-aware training with a learnable scaling factor per weight tensor, and reports that a balanced set of four levels at -1.5, -0.5, 0.5 and 1.5 trains more smoothly than the usual -2, -1, 0 and 1. The embedding table is quantised to 4 bits and the key-value cache to 8 bits, and low-rank adapters are fine-tuned afterwards to claw back the quality the compression costs. The server model takes a different route, compressed after training to 3.56 bits per weight with Adaptive Scalable Texture Compression, a GPU texture format whose fixed-function decode hardware on Apple GPUs unpacks the weights at no cost to the compute cores.

The report also spells out the KV cache sharing the framework announcement only named. Apple splits the transformer so that Block 1 holds 62.5 percent of the layers and Block 2 the remaining 37.5 percent with its key and value projections removed, reusing Block 1’s cache instead. That cuts KV cache memory by 37.5 percent, and because Block 2 produces no keys or values, prefill skips its computation entirely, which Apple says cuts time to first token by about the same 37.5 percent.

Apple rebuilt how the on-device model is trained. The company first trained a dense model on about 14T tokens, sparse-upcycled it into a 64-expert mixture-of-experts version, where only part of the model runs per token, using 1T high-quality tokens, then retrained the dense model on its last 10 percent of tokens against a distillation loss from that MoE teacher. Apple states this cut the cost of training the teacher by 90 percent and removed the need for structural pruning. The server model was trained on 8192 v5p Cloud TPU chips for 13.4T tokens.

For the language expansion the report states the models are designed to support 16 languages, built on a text tokenizer grown from a 100k to a 150k vocabulary and a continued pre-training mix whose multilingual share rose from 8 percent to 30 percent. In Apple’s own human evaluation on US English text prompts, graders preferred the on-device model over Qwen-2.5-3B on 35.3 percent of prompts against 12.9 percent the other way, while against Gemma-3-4B the split was 21.0 percent to 21.9 percent. The report is on arXiv under a Creative Commons Attribution 4.0 license.

Liquid AI released LFM2 on July 10, 2025, three open-weight checkpoints of 350M, 700M and 1.2B parameters aimed at the CPUs inside phones, laptops and vehicles. The company reports 2x faster decode and prefill speed on CPU than Qwen3, and describes the models as built for millisecond latency and offline operation on the device rather than in a data centre.

The architecture is a hybrid of 16 blocks, 10 of them gated short convolutions and 6 grouped query attention. A short convolution mixes each token with a handful of its neighbours instead of attending over the whole history, which is cheap on a phone CPU and keeps the attention cache small, while the six attention blocks preserve the recall that pure convolutions lose. Liquid AI says the layout came out of its STAR architecture search, which it ran against measured peak memory and measured prefill plus decode speed on Qualcomm Snapdragon embedded SoC CPUs rather than against proxy metrics.

Liquid AI benchmarked the models on a Samsung Galaxy S24 Ultra with a Qualcomm Snapdragon SoC and on an AMD Ryzen HX370 laptop, using Q4_0 in llama.cpp and 8da4w in ExecuTorch. In its llama.cpp charts LFM2-350M clears 1,300 tokens per second of prefill and runs at roughly 190 tokens per second of decode on the Galaxy S24 at a 128-token sequence, falling to around 120 tokens per second of decode at 4,096 tokens. The company states that LFM2-700M stays faster than Qwen3-0.6B on both decode and prefill in both runtimes despite being 16 percent larger, and that the CPU gains should carry over to GPUs and NPUs once kernels are optimised.

The models are small enough to ship whole, with Liquid AI’s own Q4_0 GGUF builds at 219 MB for LFM2-350M and 696 MB for LFM2-1.2B. On Liquid AI’s internal evaluation table LFM2-1.2B scores 55.23 on MMLU and 74.89 on IFEval against 59.11 and 73.98 for Qwen3-1.7B, a model with 47 percent more parameters, while LFM2-700M reaches 49.9 on MMLU against 40.08 for Gemma 3 1B IT. Liquid AI notes that it evaluated Qwen3 in non-reasoning mode only, on the grounds that reasoning traces run past the output budgets that matter on edge devices.

Weights are on Hugging Face, with the models also reachable through the Liquid Playground and OpenRouter, and Liquid AI points developers at llama.cpp and ExecuTorch for local testing. The licence is an open licence based on Apache 2.0 that permits academic and research use freely and commercial use by companies under $10 million in revenue, with anyone above that threshold directed to contact the company for a commercial licence. All three checkpoints were trained on 10T tokens, roughly 75 percent English, 20 percent multilingual and 5 percent code, with the context extended to 32K during pre-training.

Update, September 23, 2025. Liquid AI added LFM2-2.6B, which widens the stack to 30 blocks, 22 of them convolutions and 8 attention. The company reports 82.41 percent on GSM8K and 79.56 percent on IFEval, and says the model outperforms Llama 3.2-3B-Instruct, Gemma 3 4B IT and SmolLM3-3B. It ships on Hugging Face under the same licence.

Update, November 28, 2025. Liquid AI published an LFM2 technical report covering the dense 350M to 2.6B models plus an 8.3B mixture-of-experts variant with 1.5B active parameters, where only part of the model runs per token. Measuring on a Samsung Galaxy S25 with a Snapdragon 8 Elite in llama.cpp at Q4_0, it reports LFM2-350M at 1,067 tokens per second of prefill and 194.1 tokens per second of decode on a 1K-token prompt, and LFM2-2.6B at 143 and 33.8 against 57 and 17.2 for Qwen3-4B. The report names ExecuTorch, llama.cpp and vLLM as the shipped deployment packages.

Hugging Face released SmolLM3 on July 8, 2025, a 3B model trained on 11.2 trillion tokens that takes up to 128k tokens of context, covers six languages and answers in either of two modes. It is the successor to SmolLM2, whose largest model was 1.7B with an 8k context window and, in Hugging Face’s own words, primarily understands and generates content in English.

The longer context comes from an architecture change plus a separate training stage. Hugging Face removed rotary position embeddings from every fourth layer, a technique it calls NoPE, and replaced multi-head attention with grouped-query attention to shrink the key-value cache during inference. After the main pretraining run it trained the model on another 100 billion tokens in two steps, 4k to 32k and then 32k to 64k, and YaRN, a method for extrapolating past the trained length, carries it to 128k tokens at inference, though the published configuration ships set to 64k and has to be edited to go further. Multilingual text made up 12 percent of the web data at every pretraining stage, and Hugging Face lists English, French, Spanish, German, Italian and Portuguese as supported.

Hugging Face’s own base-model figures put SmolLM3 at 76.2 on HellaSwag, 65.6 on ARC and 79.0 on BoolQ, ahead of both Llama 3.2 3B and Qwen2.5 3B and ahead of the larger Qwen3 4B on all three. Qwen3 4B stays in front on maths and code, at 51.2 against 46.1 on MATH and 54.9 against 30.5 on HumanEval+, and on the Ruler 64k long-context test Llama 3.2 3B leads at 72.9 against 67.9 for SmolLM3. On the Flores-200 translation benchmark SmolLM3 scores 56.3 against 55.8 for Qwen3 4B and 54.9 for Qwen2.5 3B, and its multilingual chart shows it ahead of both 3B rivals in all five non-English languages and behind Qwen3 4B in all five.

A flag in the system prompt, /think or /no_think, decides whether the instruct model reasons before it answers. Hugging Face reports the reasoning mode at 36.7 percent on the AIME 2025 maths competition against 9.3 percent without it, 41.7 against 35.7 on GPQA Diamond and 30.5 against 15.2 on LiveCodeBench v4. Qwen3 4B leads on most of the eight tests in that comparison in both modes, at 58.8 on AIME 2025 and 52.9 on LiveCodeBench, though SmolLM3 without reasoning tops it on the IFEval instruction-following test at 76.7 to 68.9.

Hugging Face published the recipe as well as the weights. Pretraining ran in three stages that moved web data from 85 percent to 75 and then 63 percent while code rose from 12 percent to 24 and maths from 3 percent to 13, each share drawn from named public datasets, and the company released the training configs with the exact data weights along with intermediate checkpoints. Both the base and instruct models are on Hugging Face under the Apache 2.0 license, and the model card names llama.cpp, ONNX, MLX, MLC and ExecuTorch for local inference. The 4-bit GGUF published by ggml-org on release day is 1.92 GB, against 3.27 GB for the 8-bit build for MLX and 6.15 GB for the bfloat16 weights.