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Model comparison

GPT-4.1 vs LFM2.5-8B-A1B

Data verified

Head-to-head evidence from 13 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

OpenAI
50.93/100
Margin
9.7pts
← winning
41.25/100
1 category wins1 category wins

BenchAlign evidence: GPT-4.1 supported; LFM2.5-8B-A1B estimated. Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-4.1 and LFM2.5-8B-A1B share 13 comparable benchmark results. 2 of 8 categories are comparable. 8 results are unique to GPT-4.1; 5 to LFM2.5-8B-A1B.

Updated July 16, 2026
Shared results
13
GPT-4.1 only
8
LFM2.5-8B-A1B only
5
Comparable categories
2 / 8

Pick GPT-4.1 if you want the stronger benchmark profile. LFM2.5-8B-A1B only becomes the better choice if mathematics is the priority or you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 13 shared benchmark results across 5 evidence categories; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

GPT-4.1 is clearly ahead on the provisional aggregate, 56 to 37. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-4.1's sharpest advantage is in instruction following, where it averages 87.4 against 68.8. The single biggest benchmark swing on the page is IFEval, 87.4% to 91.8%. LFM2.5-8B-A1B does hit back in mathematics, so the answer changes if that is the part of the workload you care about most.

GPT-4.1 is also the more expensive model on tokens at $2.00 input / $8.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for LFM2.5-8B-A1B. That is roughly Infinityx on output cost alone. LFM2.5-8B-A1B is the reasoning model in the pair, while GPT-4.1 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. GPT-4.1 gives you the larger context window at 1M, compared with 128K for LFM2.5-8B-A1B.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for GPT-4.1 and LFM2.5-8B-A1B
CategoryGPT-4.1ΔLFM2.5-8B-A1B
MathGPT-4.14.1Margin 45.9LFM2.5-8B-A1B50.0
Inst. FollowingGPT-4.187.4Margin 18.6LFM2.5-8B-A1B68.8
CodingGPT-4.154.6MarginNo overlapLFM2.5-8B-A1BNot measured
KnowledgeGPT-4.166.3MarginNo overlapLFM2.5-8B-A1BNot measured

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · GPT-4.1B · LFM2.5-8B-A1B
  1. IFEval

    Inst. Following
    Source ↗
    A 87.4%B 91.8%
    Winner: LFM2.5-8B-A1BΔ 4.4
    IFEval: GPT-4.1 scored 87.4%; LFM2.5-8B-A1B scored 91.8%. LFM2.5-8B-A1B wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricGPT-4.1LFM2.5-8B-A1BComparison
Input / output priceUSD per 1M tokensGPT-4.1$2 input / $8 outputLFM2.5-8B-A1B$0 input / $0 outputLFM2.5-8B-A1B has the lower combined listed price.
Generation speedtokens per secondGPT-4.1108 tok/sLFM2.5-8B-A1BNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenGPT-4.11.02 sLFM2.5-8B-A1BNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensGPT-4.11MLFM2.5-8B-A1B128KGPT-4.1 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkGPT-4.1LFM2.5-8B-A1BResult
τ²-bench resultsSource 47.1%16.1%GPT-4.1 leads
Gert LabsSource 25.65%Not comparable
BFCL v4Source 49.7%Not comparable
Coding
BenchmarkGPT-4.1LFM2.5-8B-A1BResult
SWE-bench VerifiedSource 54.6%Not comparable
Terminal-Bench HardSource 13.6%4.5%GPT-4.1 leads
AA-SciCodeSource 38.1%7.8%GPT-4.1 leads
Reasoning
BenchmarkGPT-4.1LFM2.5-8B-A1BResult
AA-LCRSource 61.0%0.0%GPT-4.1 leads
CritPtSource 0.0%0.0%Tie
Knowledge
BenchmarkGPT-4.1LFM2.5-8B-A1BResult
MMLUSource 90.2%Not comparable
GPQASource 66.3%Not comparable
Artificial Analysis Intelligence IndexSource 19.4%8.3%GPT-4.1 leads
AA-GPQA DiamondSource 66.6%51.3%GPT-4.1 leads
AA-HLESource 4.6%6.9%LFM2.5-8B-A1B leads
AA-Omniscience IndexSource -36.2%-33.3%LFM2.5-8B-A1B leads
AA-Omniscience AccuracySource 24.2%9.4%GPT-4.1 leads
AA-Omniscience Hallucination RateSource 79.6%47.0%LFM2.5-8B-A1B leads
MathLFM2.5-8B-A1B wins
BenchmarkGPT-4.1LFM2.5-8B-A1BResult
FrontierMath v2 (Tiers 1-3)Source 5.517%Not comparable
FrontierMath v2 (Tier 4)Source 0.000%Not comparable
MATH-500Source 88.8%Not comparable
AIME 2025Source 42.5%Not comparable
AIME26Source 50.0%Not comparable
Multimodal
BenchmarkGPT-4.1LFM2.5-8B-A1BResult
AA-MMMU-ProSource 61.2%Not comparable
Design Arena WebsiteSource 1073Not comparable
Inst. FollowingGPT-4.1 wins
BenchmarkGPT-4.1LFM2.5-8B-A1BResult
IFEvalSource 87.4%91.8%LFM2.5-8B-A1B leads
AA-IFBenchSource 43.0%55.6%LFM2.5-8B-A1B leads
IFBenchSource 56.5%Not comparable
Frequently Asked Questions (3)

Which is better, GPT-4.1 or LFM2.5-8B-A1B?

GPT-4.1 is ahead on BenchLM's provisional leaderboard, 56 to 37. The biggest single separator in this matchup is IFEval, where the scores are 87.4% and 91.8%.

Which is better for math, GPT-4.1 or LFM2.5-8B-A1B?

LFM2.5-8B-A1B has the edge for math in this comparison, averaging 50 versus 4.1. GPT-4.1 stays close enough that the answer can still flip depending on your workload.

Which is better for instruction following, GPT-4.1 or LFM2.5-8B-A1B?

GPT-4.1 has the edge for instruction following in this comparison, averaging 87.4 versus 68.8. Inside this category, AA-IFBench is the benchmark that creates the most daylight between them.

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Last updated: July 16, 2026

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