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Model comparison

Claude Opus 4.5 vs LFM2.5-8B-A1B

Data verified

Head-to-head evidence from 15 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

64.13/100
Margin
22.9pts
← winning
41.25/100
2 category wins0 category wins

Verified leaderboard positions: Claude Opus 4.5 #19; LFM2.5-8B-A1B unranked

BenchAlign evidence: Claude Opus 4.5 supported; LFM2.5-8B-A1B estimated. Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Opus 4.5 and LFM2.5-8B-A1B share 15 comparable benchmark results. 2 of 8 categories are comparable. 45 results are unique to Claude Opus 4.5; 3 to LFM2.5-8B-A1B.

Updated July 16, 2026
Shared results
15
Claude Opus 4.5 only
45
LFM2.5-8B-A1B only
3
Comparable categories
2 / 8

Pick Claude Opus 4.5 if you want the stronger benchmark profile. LFM2.5-8B-A1B only becomes the better choice if you want the cheaper token bill or you want the stronger reasoning-first profile.

Confidence note. This is a partial-evidence comparison with 15 shared benchmark results across 6 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

Claude Opus 4.5 is clearly ahead on the provisional aggregate, 71 to 37. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Opus 4.5's sharpest advantage is in mathematics, where it averages 57.5 against 50. The single biggest benchmark swing on the page is AIME26, 95.1% to 50.0%.

Claude Opus 4.5 is also the more expensive model on tokens at $5.00 input / $25.00 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 Claude Opus 4.5 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. Claude Opus 4.5 gives you the larger context window at 200K, 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 Claude Opus 4.5 and LFM2.5-8B-A1B
CategoryClaude Opus 4.5ΔLFM2.5-8B-A1B
MathClaude Opus 4.557.5Margin← 7.5LFM2.5-8B-A1B50.0
Inst. FollowingClaude Opus 4.569.5Margin← 0.7LFM2.5-8B-A1B68.8
AgenticClaude Opus 4.562.6MarginNo overlapLFM2.5-8B-A1BNot measured
CodingClaude Opus 4.571.7MarginNo overlapLFM2.5-8B-A1BNot measured
ReasoningClaude Opus 4.564.4MarginNo overlapLFM2.5-8B-A1BNot measured
KnowledgeClaude Opus 4.558.5MarginNo overlapLFM2.5-8B-A1BNot measured
MultilingualClaude Opus 4.585.7MarginNo overlapLFM2.5-8B-A1BNot measured
MultimodalClaude Opus 4.569.9MarginNo overlapLFM2.5-8B-A1BNot measured

Decisive benchmark drivers

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

More
A · Claude Opus 4.5B · LFM2.5-8B-A1B

  1. AIME26

    Math
    Source ↗
    A 95.1%B 50.0%
    Winner: Claude Opus 4.5Δ 45.1
    AIME26: Claude Opus 4.5 scored 95.1%; LFM2.5-8B-A1B scored 50.0%. Claude Opus 4.5 wins this benchmark.

  2. IFBench

    Inst. Following
    Source ↗
    A 58%B 56.5%
    Winner: Claude Opus 4.5Δ 1.5
    IFBench: Claude Opus 4.5 scored 58%; LFM2.5-8B-A1B scored 56.5%. Claude Opus 4.5 wins this benchmark.

  3. IFEval

    Inst. Following
    Source ↗
    A 90.9%B 91.8%
    Winner: LFM2.5-8B-A1BΔ 0.9
    IFEval: Claude Opus 4.5 scored 90.9%; 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.

MetricClaude Opus 4.5LFM2.5-8B-A1BComparison
Input / output priceUSD per 1M tokensClaude Opus 4.5$5 input / $25 outputLFM2.5-8B-A1B$0 input / $0 outputLFM2.5-8B-A1B has the lower combined listed price.
Generation speedtokens per secondClaude Opus 4.546 tok/sLFM2.5-8B-A1BNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Opus 4.51.01 sLFM2.5-8B-A1BNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Opus 4.5200KLFM2.5-8B-A1B128KClaude Opus 4.5 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkClaude Opus 4.5LFM2.5-8B-A1BResult
Terminal-Bench 2.0Source 59.3%—Not comparable
OSWorld-VerifiedSource 66.3%—Not comparable
OSWorldSource 66.3%—Not comparable
Claw-EvalSource 59.6%—Not comparable
QwenClawBenchSource 52.3%—Not comparable
τ³-bench resultsSource 70.2%—Not comparable
VITA-BenchSource 23.3%—Not comparable
DeepPlanningSource 26.4%—Not comparable
ToolathlonSource 43.5%—Not comparable
MCP AtlasSource 42.3%—Not comparable
MCP-TasksSource 71.8%—Not comparable
WideResearchSource 76.4%—Not comparable
CyberGymSource 50.6%—Not comparable
τ²-bench resultsSource 86.3%16.1%Claude Opus 4.5 leads
Gert LabsSource 64.23%—Not comparable
JobBenchSource 32.3%—Not comparable
BFCL v4Source —49.7%Not comparable
Coding
BenchmarkClaude Opus 4.5LFM2.5-8B-A1BResult
SWE-bench VerifiedSource 80.9%—Not comparable
LiveCodeBench v6Source 84.8%—Not comparable
SWE-bench ProSource 57.1%—Not comparable
SWE MultilingualSource 77.5%—Not comparable
NL2RepoSource 43.2%—Not comparable
Terminal-Bench HardSource 40.9%4.5%Claude Opus 4.5 leads
AA-SciCodeSource 47.0%7.8%Claude Opus 4.5 leads
Reasoning
BenchmarkClaude Opus 4.5LFM2.5-8B-A1BResult
LongBench v2Source 64.4%—Not comparable
AI-NeedleSource 74%—Not comparable
AA-LCRSource 65.3%0.0%Claude Opus 4.5 leads
CritPtSource 0.3%0.0%Claude Opus 4.5 leads
Knowledge
BenchmarkClaude Opus 4.5LFM2.5-8B-A1BResult
GPQASource 87%—Not comparable
SuperGPQASource 70.6%—Not comparable
MMLU-ProSource 89.5%—Not comparable
MMLU-ReduxSource 96.6%—Not comparable
C-EvalSource 92.2%—Not comparable
HLESource 30.8%—Not comparable
Artificial Analysis Intelligence IndexSource 34.7%8.3%Claude Opus 4.5 leads
AA-GPQA DiamondSource 81.0%51.3%Claude Opus 4.5 leads
AA-HLESource 12.9%6.9%Claude Opus 4.5 leads
AA-Omniscience IndexSource -3.9%-33.3%Claude Opus 4.5 leads
AA-Omniscience AccuracySource 40.7%9.4%Claude Opus 4.5 leads
AA-Omniscience Hallucination RateSource 75.4%47.0%LFM2.5-8B-A1B leads
AA MMLU-ProSource 88.9%—Not comparable
MathClaude Opus 4.5 wins
BenchmarkClaude Opus 4.5LFM2.5-8B-A1BResult
AIME26Source 95.1%50.0%Claude Opus 4.5 leads
HMMT Feb 2025Source 92.9%—Not comparable
HMMT Nov 2025Source 93.3%—Not comparable
HMMT Feb 2026Source 85.3%—Not comparable
MMAnswerBenchSource 84.0%—Not comparable
FrontierMath v2 (Tiers 1-3)Source 20.690%—Not comparable
FrontierMath v2 (Tier 4)Source 4.167%—Not comparable
MATH-500Source —88.8%Not comparable
AIME 2025Source —42.5%Not comparable
Multilingual
BenchmarkClaude Opus 4.5LFM2.5-8B-A1BResult
MMLU-ProXSource 85.7%—Not comparable
NOVA-63Source 56.7%—Not comparable
Multimodal
BenchmarkClaude Opus 4.5LFM2.5-8B-A1BResult
MMMU-ProSource 70.6%—Not comparable
MathVisionSource 74.3%—Not comparable
CharXivSource 68.5%—Not comparable
VideoMMMUSource 84.4%—Not comparable
ScreenSpot ProSource 45.7%—Not comparable
V*Source 67.0%—Not comparable
AA-MMMU-ProSource 71.2%—Not comparable
Design Arena WebsiteSource 1281—Not comparable
Inst. FollowingClaude Opus 4.5 wins
BenchmarkClaude Opus 4.5LFM2.5-8B-A1BResult
IFEvalSource 90.9%91.8%LFM2.5-8B-A1B leads
IFBenchSource 58%56.5%Claude Opus 4.5 leads
AA-IFBenchSource 43.0%55.6%LFM2.5-8B-A1B leads
Frequently Asked Questions (3)

Which is better, Claude Opus 4.5 or LFM2.5-8B-A1B?

Claude Opus 4.5 is ahead on BenchLM's provisional leaderboard, 71 to 37. The biggest single separator in this matchup is AIME26, where the scores are 95.1% and 50.0%.

Which is better for math, Claude Opus 4.5 or LFM2.5-8B-A1B?

Claude Opus 4.5 has the edge for math in this comparison, averaging 57.5 versus 50. Inside this category, AIME26 is the benchmark that creates the most daylight between them.

Which is better for instruction following, Claude Opus 4.5 or LFM2.5-8B-A1B?

Claude Opus 4.5 has the edge for instruction following in this comparison, averaging 69.5 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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