Model comparison
Claude Opus 4.5 vs o3-mini
Head-to-head evidence from 8 shared benchmark results across 4 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Opus 4.5 #38 (Supported); o3-mini #141 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Opus 4.5 and o3-mini share 8 comparable benchmark results. 3 of 8 categories are comparable. 51 results are unique to Claude Opus 4.5; 2 to o3-mini.
Updated July 24, 2026- Shared results
- 8
- Claude Opus 4.5 only
- 51
- o3-mini only
- 2
- Comparable categories
- 3 / 8
Pick Claude Opus 4.5 if you want the stronger benchmark profile. o3-mini only becomes the better choice if instruction following is the priority or you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 8 shared benchmark results across 4 evidence categories; 3 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 BenchAlign aggregate, 63.43 to 46.59. 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 coding, where it averages 71.7 against 49.3. The single biggest benchmark swing on the page is SWE-bench Verified, 80.9% to 49.3%. o3-mini does hit back in instruction following, so the answer changes if that is the part of the workload you care about most.
Claude Opus 4.5 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $1.10 input / $4.40 output per 1M tokens for o3-mini. That is roughly 5.7x on output cost alone. o3-mini 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.
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 | Claude Opus 4.5 | Δ | o3-mini |
|---|---|---|---|
| Inst. Following | Claude Opus 4.569.5 | Margin→ 24.4 | o3-mini93.9 |
| Coding | Claude Opus 4.571.7 | Margin← 22.4 | o3-mini49.3 |
| Knowledge | Claude Opus 4.558.1 | Margin→ 19.1 | o3-mini77.2 |
| Agentic | Claude Opus 4.562.6 | MarginNo overlap | o3-miniNot measured |
| Reasoning | Claude Opus 4.564.4 | MarginNo overlap | o3-miniNot measured |
| Math | Claude Opus 4.557.5 | MarginNo overlap | o3-miniNot measured |
| Multilingual | Claude Opus 4.585.7 | MarginNo overlap | o3-miniNot measured |
| Multimodal | Claude Opus 4.569.9 | MarginNo overlap | o3-miniNot measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
SWE-bench Verified
CodingA 80.9%B 49.3%Winner: Claude Opus 4.5Δ 31.6SWE-bench Verified: Claude Opus 4.5 scored 80.9%; o3-mini scored 49.3%. Claude Opus 4.5 wins this benchmark. - Source ↗
GPQA
KnowledgeA 87%B 77.2%Winner: Claude Opus 4.5Δ 9.8GPQA: Claude Opus 4.5 scored 87%; o3-mini scored 77.2%. Claude Opus 4.5 wins this benchmark. - Source ↗
IFEval
Inst. FollowingA 90.9%B 93.9%Winner: o3-miniΔ 3IFEval: Claude Opus 4.5 scored 90.9%; o3-mini scored 93.9%. o3-mini wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Opus 4.5 | o3-mini | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Opus 4.5$5 input / $25 output | o3-mini$1.1 input / $4.4 output | o3-mini has the lower combined listed price. |
| Generation speedtokens per second | Claude Opus 4.546 tok/s | o3-mini160 tok/s | o3-mini has the higher measured throughput. |
| First-answer latencyseconds to first token | Claude Opus 4.51.01 s | o3-mini7.12 s | Claude Opus 4.5 reaches the first token sooner. |
| Context windowmaximum listed tokens | Claude Opus 4.5200K | o3-mini200K | Listed context windows are equal. |
Benchmark Deep Dive
Agentic16 benchmarks
| Benchmark | Claude Opus 4.5 | o3-mini | Result |
|---|---|---|---|
| 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% | 28.7% | Claude Opus 4.5 leads |
| Gert LabsSource | 64.23% | — | Not comparable |
| JobBenchSource | 32.3% | — | Not comparable |
CodingClaude Opus 4.5 wins6 benchmarks
| Benchmark | Claude Opus 4.5 | o3-mini | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 80.9% | 49.3% | Claude Opus 4.5 leads |
| LiveCodeBench v6Source | 84.8% | — | Not comparable |
| SWE-bench ProSource | 57.1% | — | Not comparable |
| SWE MultilingualSource | 77.5% | — | Not comparable |
| NL2RepoSource | 43.2% | — | Not comparable |
| AA-SciCodeSource | 47.0% | 39.9% | Claude Opus 4.5 leads |
Reasoning4 benchmarks
Knowledgeo3-mini wins14 benchmarks
| Benchmark | Claude Opus 4.5 | o3-mini | Result |
|---|---|---|---|
| GPQASource | 87% | 77.2% | Claude Opus 4.5 leads |
| 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% | 19.0% | Claude Opus 4.5 leads |
| AA-GPQA DiamondSource | 81.0% | 74.8% | Claude Opus 4.5 leads |
| AA-HLESource | 12.9% | 8.7% | Claude Opus 4.5 leads |
| AA-Omniscience IndexSource | -3.9% | — | Not comparable |
| AA-Omniscience AccuracySource | 40.7% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 75.4% | — | Not comparable |
| AA MMLU-ProSource | 88.9% | — | Not comparable |
| MMLUSource | — | 86.9% | Not comparable |
Math8 benchmarks
| Benchmark | Claude Opus 4.5 | o3-mini | Result |
|---|---|---|---|
| AIME26Source | 95.1% | — | Not comparable |
| 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 |
| AIME 2024Source | — | 87.3% | Not comparable |
Multilingual2 benchmarks
Multimodal8 benchmarks
| Benchmark | Claude Opus 4.5 | o3-mini | Result |
|---|---|---|---|
| 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 | 1277 | — | Not comparable |
Frequently Asked Questions (4)
Which is better, Claude Opus 4.5 or o3-mini?
Claude Opus 4.5 is ahead on BenchLM's BenchAlign leaderboard, 63.43 to 46.59. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 80.9% and 49.3%.
Which is better for knowledge tasks, Claude Opus 4.5 or o3-mini?
o3-mini has the edge for knowledge tasks in this comparison, averaging 77.2 versus 58.1. Inside this category, Artificial Analysis Intelligence Index is the benchmark that creates the most daylight between them.
Which is better for coding, Claude Opus 4.5 or o3-mini?
Claude Opus 4.5 has the edge for coding in this comparison, averaging 71.7 versus 49.3. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
Which is better for instruction following, Claude Opus 4.5 or o3-mini?
o3-mini has the edge for instruction following in this comparison, averaging 93.9 versus 69.5. Inside this category, IFEval is the benchmark that creates the most daylight between them.