Parameters
8.3B total / 1.5B active
MoE: total / active
Architecture
LFM2 (Hybrid MoE)
Released
28.05.2026
License
LFM Open License v1.0
Input Modalities
Output Modalities
Context (native)
128,000 tokens
Context (extended)
128,000 tokens
About
LFM2.5-8B-A1B is Liquid AI's reasoning-tuned, general-purpose Mixture of Experts (MoE) model designed for on-device deployment - an on-device personal assistant that chains tool calls and follows complex instructions on all devices. It is a sparse hybrid of 18 double-gated convolution blocks and 6 Grouped-Query Attention (GQA) full-attention layers (24 layers total): 8.3B total parameters with only 1.5B active per token (top-4 routing across 32 experts), with Rotary Position Embedding (RoPE) base frequency 5M and a 128,000-token context window.
It was trained with a 38-trillion-token pre-training budget and large-scale reinforcement learning, and its vocabulary was expanded in place to 128K entries. LFM2.5-8B-A1B is text-only, speaks English, Arabic, Chinese, French, German, Italian, Japanese, Korean, Portuguese and Spanish, uses a ChatML-like chat template, and supports Pythonic function calling in a four-step tool-use flow. It is "compressed performance": competitive with much larger dense and MoE models on instruction following and agentic tasks, and is the fastest model in its size class - up to 18.5K output tokens per second at high concurrency on a single H100 - with day-one support for llama.cpp, MLX, vLLM and SGLang. A 328M speculative decoding drafter (LFM2.5-8B-A1B-DSpark) pairs with it for ~2.5x faster decoding with identical outputs.
Recommended for agentic workflows, tool use, structured outputs, multilingual assistants and on-device personal-assistant applications; not the best fit for heavy programming or knowledge-intensive question answering without retrieval. Released May 28, 2026 under the LFM Open License v1.0.
Training Data 38 trillion tokens pre-training, post-training with SFT and RL
Benchmark Scores
| Benchmark | Score | Date | Standing |
|---|---|---|---|
|
BrowseComp
general_agent
|
7.42%
|
— |
#40/45
better than 11%
|
|
TAU2-Bench
general_agent
|
16.10
|
— |
#21/21
better than 0%
|
|
BFCL-V4
general_agent
|
45.02%
|
— |
#21/27
better than 23%
|
|
MMLU-Pro
knowledge
|
10.00%
|
— |
#47/48
better than 2%
|
|
MMLU-Redux
knowledge
|
34.45%
|
— |
#25/30
better than 10%
|
|
Humanity's Last Exam
stem_reasoning
|
9.09%
|
— |
#64/71
better than 10%
|
|
Terminal Bench 2.1
coding_agent
|
1.66%
|
— |
#42/44
better than 2%
|
|
GPQA Diamond
stem_reasoning
|
18.70%
|
— |
#73/80
better than 8%
|
|
SuperGPQA
knowledge
|
18.69%
|
— |
#26/28
better than 7%
|
|
BrowseComp-zh
general_agent
|
14.86%
|
— |
#9/13
better than 33%
|
|
AA-LCR
long_context
|
0.00
|
— |
#42/42
better than 0%
|
|
NoLiMa
long_context
|
0.50
|
— |
#9/9
better than 0%
|
|
Gaia2
general_agent
|
23.47%
|
— |
#7/12
better than 45%
|
|
GDPVal-AA v2
general_agent
|
0.00
|
— |
#33/38
better than 0%
|
|
LongBench v2
long_context
|
12.44%
|
— |
#20/22
better than 10%
|
|
Claw-Eval Avg
coding_agent
|
2.70
|
— |
#40/40
better than 0%
|
|
TAU3-Bench
general_agent
|
3.25%
|
— |
#20/21
better than 5%
|
|
QwenClawBench
coding_agent
|
4.50
|
— |
#17/17
better than 0%
|
|
LiveCodeBench v6
stem_reasoning
|
26.74%
|
— |
#47/49
better than 4%
|
|
LCB-Pro 25Q2 (Easy)
stem_reasoning
|
30.33%
|
— |
#7/9
better than 25%
|
|
LCB-Pro 25Q2 (Medium)
stem_reasoning
|
0.00
|
— |
#6/9
better than 0%
|
|
OJBench
stem_reasoning
|
8.22%
|
— |
#21/22
better than 5%
|
|
SciCode
|
3.43%
|
— |
#26/27
better than 4%
|
|
AIME 26
stem_reasoning
|
45.79%
|
— |
#40/45
better than 11%
|
|
HMMT Feb 26
stem_reasoning
|
23.32%
|
— |
#40/44
better than 9%
|
|
MATH-500
math
|
57.35%
|
— |
#6/11
better than 50%
|
|
IFBench
instruction_following
|
46.02%
|
— |
#39/42
better than 7%
|
|
WildClawBench
coding_agent
|
4.50
|
— |
#20/20
better than 0%
|
|
SWE-bench Verified
coding_agent
|
0.40
|
— |
#60/60
better than 0%
|
|
AIME 2025
stem_reasoning
|
23.30%
|
— |
#20/24
better than 17%
|
|
LongBenchPro
long_context
|
20.25%
|
— |
#9/10
better than 11%
|
|
IFEval
instruction_following
|
90.40%
|
— |
#13/26
better than 52%
|
|
Multi-IF
instruction_following
|
63.73%
|
— |
#8/13
better than 42%
|
|
SWE-bench Pro
coding_agent
|
0.45%
|
— |
#75/77
better than 3%
|
What is a good BrowseComp score? What is a good TAU2-Bench score? What is a good BFCL-V4 score?
Hardware Requirements
Estimated VRAM per quantization at 4,096 tokens context — MoE: all experts must fit in VRAM, only 1.5B are active per token
| Quantization | Weights | KV Cache | Total VRAM | On your hardware |
|---|---|---|---|---|
| FP16 — 16-bit | 16.6 GB | 0.2 GB | 17.7 GB | Which GPUs can run it? Calculate on your GPU |
| INT8 — 8-bit | 8.3 GB | 0.1 GB | 8.8 GB | Which GPUs can run it? Calculate on your GPU |
| INT4 — 4-bit | 4.2 GB | 0.1 GB | 4.4 GB | Which GPUs can run it? Calculate on your GPU |
| FP4 — 4-bit | 4.2 GB | 0.1 GB | 4.4 GB | Which GPUs can run it? Calculate on your GPU |
Consumer GPUs that fit this model with a single card (INT4):
Architecture
- Attention
- Hybrid Attention (32:8)
- MoE
- 32 experts · top-4 per token
- Layers
- 24
- Hidden size
- 2048
- Context
- 128K tokens
- Parameters
- 8300M
- Active params
- 1500M
Source: Hugging Face config.json · Lfm2MoeForCausalLM · exact layer pattern · model repo
LFM2.5-8B-A1B-DSpark (328M, ~2.5x faster decoding)
Training Pipeline
-
1
pretraining
Extended pre-training (38T tokens)
38-trillion-token pre-training budget building on the LFM2 architecture; vocabulary expanded in place to 128K entries.
-
2
sft
Supervised fine-tuning
Post-training with SFT (general-purpose reasoning-tuned checkpoint).
-
3
rl
Large-scale reinforcement learning
Large-scale RL for reasoning, instruction following and agentic tool use.
Training & Evaluation Datasets
| Name | Role | Size | Modalities | Collection |
|---|---|---|---|---|
| AA-Omniscience (Artificial Analysis) | evaluation | — | — | |
| IFEval / IFBench / Multi-IF | evaluation | — | — | |
| MATH500 / AIME25 / AIME26 | evaluation | — | — | |
| BFCL v3 / BFCL v4 | evaluation | — | — | |
| Tau-squared Telecom / Retail | evaluation | — | — |
Linked Resources
LFM2.5-8B-A1B: An Even Better On-Device Mixture of Experts
https://www.liquid.ai/blog/lfm2-5-8b-a1b
LFM2 Technical Report
https://arxiv.org/abs/2511.23404
In-Place Tokenizer Expansion for Pre-trained LLMs
https://arxiv.org/abs/2607.15232
Liquid LFM documentation
https://docs.liquid.ai/lfm/getting-started/welcome
Try LFM (Liquid AI playground)
https://playground.liquid.ai/
BibTeX citations (Liquid AI, 2026)
https://huggingface.co/LiquidAI/LFM2.5-8B-A1B
Trend Analysis
24h Change
+1.4%
7d Change
+9.9%
Current
333,300 pulls
followers
+0.5%
downloads
+1.0%
downloads_all_time
+0.1%
likes
+0.0%
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