Model comparison
Claude Sonnet 4.5 vs o3-mini
Head-to-head evidence from 2 shared benchmark results across 2 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Sonnet 4.5 #98 (Estimated); o3-mini #141 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Sonnet 4.5 and o3-mini share 2 comparable benchmark results. 2 of 8 categories are comparable. 10 results are unique to Claude Sonnet 4.5; 8 to o3-mini.
Updated July 24, 2026- Shared results
- 2
- Claude Sonnet 4.5 only
- 10
- o3-mini only
- 8
- Comparable categories
- 2 / 8
Pick Claude Sonnet 4.5 if you want the stronger benchmark profile. o3-mini 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 2 shared benchmark results across 2 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 Sonnet 4.5 is clearly ahead on the BenchAlign aggregate, 52.89 to 46.59. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Sonnet 4.5's sharpest advantage is in coding, where it averages 77.2 against 49.3. The single biggest benchmark swing on the page is SWE-bench Verified, 77.2% to 49.3%.
Claude Sonnet 4.5 is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $1.10 input / $4.40 output per 1M tokens for o3-mini. That is roughly 3.4x on output cost alone. o3-mini is the reasoning model in the pair, while Claude Sonnet 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 Sonnet 4.5 | Δ | o3-mini |
|---|---|---|---|
| Coding | Claude Sonnet 4.577.2 | Margin← 27.9 | o3-mini49.3 |
| Knowledge | Claude Sonnet 4.583.4 | Margin← 6.2 | o3-mini77.2 |
| Agentic | Claude Sonnet 4.555.4 | MarginNo overlap | o3-miniNot measured |
| Reasoning | Claude Sonnet 4.513.6 | MarginNo overlap | o3-miniNot measured |
| Math | Claude Sonnet 4.511.2 | MarginNo overlap | o3-miniNot measured |
| Inst. Following | Claude Sonnet 4.5Not measured | MarginNo overlap | o3-mini93.9 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
SWE-bench Verified
CodingA 77.2%B 49.3%Winner: Claude Sonnet 4.5Δ 27.9SWE-bench Verified: Claude Sonnet 4.5 scored 77.2%; o3-mini scored 49.3%. Claude Sonnet 4.5 wins this benchmark. - Source ↗
GPQA
KnowledgeA 83.4%B 77.2%Winner: Claude Sonnet 4.5Δ 6.2GPQA: Claude Sonnet 4.5 scored 83.4%; o3-mini scored 77.2%. Claude Sonnet 4.5 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Sonnet 4.5 | o3-mini | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Sonnet 4.5$3 input / $15 output | o3-mini$1.1 input / $4.4 output | o3-mini has the lower combined listed price. |
| Generation speedtokens per second | Claude Sonnet 4.5Not available | o3-mini160 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Sonnet 4.5Not available | o3-mini7.12 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Sonnet 4.5200K | o3-mini200K | Listed context windows are equal. |
Benchmark Deep Dive
Agentic6 benchmarks
CodingClaude Sonnet 4.5 wins2 benchmarks
Reasoning1 benchmarks
| Benchmark | Claude Sonnet 4.5 | o3-mini | Result |
|---|---|---|---|
| ARC-AGI-2Source | 13.6% | — | Not comparable |
KnowledgeClaude Sonnet 4.5 wins5 benchmarks
Math4 benchmarks
Multimodal1 benchmarks
| Benchmark | Claude Sonnet 4.5 | o3-mini | Result |
|---|---|---|---|
| Design Arena WebsiteSource | 1219 | — | Not comparable |
Inst. Following1 benchmarks
| Benchmark | Claude Sonnet 4.5 | o3-mini | Result |
|---|---|---|---|
| IFEvalSource | — | 93.9% | Not comparable |
Frequently Asked Questions (3)
Which is better, Claude Sonnet 4.5 or o3-mini?
Claude Sonnet 4.5 is ahead on BenchLM's BenchAlign leaderboard, 52.89 to 46.59. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 77.2% and 49.3%.
Which is better for knowledge tasks, Claude Sonnet 4.5 or o3-mini?
Claude Sonnet 4.5 has the edge for knowledge tasks in this comparison, averaging 83.4 versus 77.2. Inside this category, GPQA is the benchmark that creates the most daylight between them.
Which is better for coding, Claude Sonnet 4.5 or o3-mini?
Claude Sonnet 4.5 has the edge for coding in this comparison, averaging 77.2 versus 49.3. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.