# Claude Sonnet 5 vs GPT-5.3 Codex

> Side-by-side benchmark comparison for Claude Sonnet 5 and GPT-5.3 Codex across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-sonnet-5-vs-gpt-5-3-codex
- Last updated: September 18, 2026

- Shared sourced benchmarks: 4
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Pick Claude Sonnet 5 if you want the stronger benchmark profile. GPT-5.3 Codex only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Claude Sonnet 5 leads overall 69.68 to 64.03.
- The clearest category separation is in agentic, where the averages are 65.9 for Claude Sonnet 5 and 61.6 for GPT-5.3 Codex.
- The biggest single benchmark swing is OSWorld-Verified in Agentic, with scores of 81.2% and 64.7%.
- Claude Sonnet 5 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Claude Sonnet 5 also has the larger context window at 1M.

## Model Snapshot

| Property | Claude Sonnet 5 | GPT-5.3 Codex |
|----------|----------|----------|
| Creator | Anthropic | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 400K |
| Overall Score | 69.68 | 64.03 |
| Benchmarks Covered | 26 | 8 |
| Pricing (input/output) | $2.00 / $10.00 | $1.75 / $14.00 |

## Category Breakdown

### Agentic

- Winner: Coming soon
- Claude Sonnet 5 public-lane score: 65.9 (Supported · #11/154)
- GPT-5.3 Codex public-lane score: 61.6 (Estimated · #15/154)

| Benchmark | Claude Sonnet 5 | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 14.6% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 80.4% | 77.3% | Claude Sonnet 5 |
| BrowseComp | 84.7% | Coming soon | Coming soon |
| HLE w/ tools | 57.4% | Coming soon | Coming soon |
| OSWorld-Verified | 81.2% | 64.7% | Claude Sonnet 5 |
| Terminal-Bench 2.1 (Vals) | 74.5% | Coming soon | Coming soon |
| ApprenticeBench | 16% | Coming soon | Coming soon |
| Gert Labs | Coming soon | 57.47% | Coming soon |
| JobBench | Coming soon | 33.7% | Coming soon |

### Coding

- Winner: Coming soon
- Claude Sonnet 5 public-lane score: 63.9 (Supported · #13/154)
- GPT-5.3 Codex public-lane score: 61.9 (Estimated · #17/154)

| Benchmark | Claude Sonnet 5 | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 85.2% | 85% | Claude Sonnet 5 |
| SWE-bench Pro | 63.2% | 56.8% | Claude Sonnet 5 |
| SWE Multilingual | 78.3% | Coming soon | Coming soon |
| SWE Multimodal | 28.1% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 80.4% | Coming soon | Coming soon |
| FrontierCode 1.1 Main | 42.7% | Coming soon | Coming soon |
| cursorBench32 | 61.5% | Coming soon | Coming soon |
| VulcanBench CII v1 | 89.2% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 82.4% | Coming soon | Coming soon |
| SWE-bench (Vals) | 79.6% | Coming soon | Coming soon |
| cursorBench40 | 34.1% | Coming soon | Coming soon |
| SWE-Rebench | Coming soon | 58.2% | Coming soon |
| Vibe Code Bench | Coming soon | 61.77% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- Claude Sonnet 5 public-lane score: 77.4 (#14/48)
- GPT-5.3 Codex public-lane score: 75.7 (Unranked · 1 rankable row)

| Benchmark | Claude Sonnet 5 | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| CharXiv | 88.3% | Coming soon | Coming soon |
| CharXiv w/o tools | 77% | Coming soon | Coming soon |

### Reasoning

- Winner: Coming soon
- Claude Sonnet 5 public-lane score: 77.4 (Unranked · 2 rankable rows)
- GPT-5.3 Codex public-lane score: 78.3 (Unranked · 2 rankable rows)

### Knowledge

- Winner: Coming soon
- Claude Sonnet 5 public-lane score: 66.5 (Supported · #20/184)
- GPT-5.3 Codex public-lane score: 65.6 (Estimated · #23/184)

| Benchmark | Claude Sonnet 5 | GPT-5.3 Codex | Winner |
|-----------|-----------|-----------|--------|
| HLE | 57.4% | Coming soon | Coming soon |
| HLE w/o tools | 43.2% | Coming soon | Coming soon |
| HLE-Verified | 31.0% | Coming soon | Coming soon |
| LABBench2 | 80.1% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 88.9% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 87.5% | Coming soon | Coming soon |

### Instruction Following

- Winner: Coming soon
- Claude Sonnet 5 public-lane score: Coming soon
- GPT-5.3 Codex public-lane score: 91.2 (#15/124)

## FAQ

### Which is better overall, Claude Sonnet 5 or GPT-5.3 Codex?

Claude Sonnet 5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Sonnet 5 and GPT-5.3 Codex?

The widest category gap is in agentic, where the averages are 65.9 for Claude Sonnet 5 and 61.6 for GPT-5.3 Codex.

### How many benchmarks does Claude Sonnet 5 cover on BenchLM?

Claude Sonnet 5 currently has 26 sourced benchmark scores on BenchLM.

### How many benchmarks does GPT-5.3 Codex cover on BenchLM?

GPT-5.3 Codex currently has 8 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Sonnet 5 vs GPT-5.3-Codex-Spark](/compare/claude-sonnet-5-vs-gpt-5-3-codex-spark)
- [GPT-5.3 Codex vs GPT-5.3-Codex-Spark](/compare/gpt-5-3-codex-vs-gpt-5-3-codex-spark)
- [Claude Sonnet 5 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-claude-sonnet-5)
- [GPT-5.3 Codex vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-gpt-5-3-codex)

## Explore More

- [Claude Sonnet 5 profile](/models/claude-sonnet-5)
- [GPT-5.3 Codex profile](/models/gpt-5-3-codex)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)