Model comparison
Claude 4.1 Opus vs GPT-5.3 Codex
Head-to-head evidence from 4 shared benchmark results across 4 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude 4.1 Opus #142 (Supported); GPT-5.3 Codex #26 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude 4.1 Opus and GPT-5.3 Codex share 4 comparable benchmark results. 1 of 8 categories are comparable. 0 results are unique to Claude 4.1 Opus; 17 to GPT-5.3 Codex.
Updated July 20, 2026- Shared results
- 4
- Claude 4.1 Opus only
- 0
- GPT-5.3 Codex only
- 17
- Comparable categories
- 1 / 8
Pick GPT-5.3 Codex if you want the stronger benchmark profile. Claude 4.1 Opus only becomes the better choice if coding is the priority or you would rather avoid the extra latency and token burn of a reasoning model.
Confidence note. This is a partial-evidence comparison with 4 shared benchmark results across 4 evidence categories; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
GPT-5.3 Codex is clearly ahead on the BenchAlign aggregate, 66.69 to 45.88. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude 4.1 Opus is also the more expensive model on tokens at $15.00 input / $75.00 output per 1M tokens, versus $1.75 input / $14.00 output per 1M tokens for GPT-5.3 Codex. That is roughly 5.4x on output cost alone. GPT-5.3 Codex is the reasoning model in the pair, while Claude 4.1 Opus 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-5.3 Codex gives you the larger context window at 400K, compared with 200K for Claude 4.1 Opus.
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 4.1 Opus | Δ | GPT-5.3 Codex |
|---|---|---|---|
| Coding | Claude 4.1 Opus74.5 | Margin← 7.3 | GPT-5.3 Codex67.2 |
| Agentic | Claude 4.1 OpusNot measured | MarginNo overlap | GPT-5.3 Codex71.4 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
SWE-bench Verified
CodingA 74.5%B 85%Winner: GPT-5.3 CodexΔ 10.5SWE-bench Verified: Claude 4.1 Opus scored 74.5%; GPT-5.3 Codex scored 85%. GPT-5.3 Codex wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude 4.1 Opus | GPT-5.3 Codex | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude 4.1 Opus$15 input / $75 output | GPT-5.3 Codex$1.75 input / $14 output | GPT-5.3 Codex has the lower combined listed price. |
| Generation speedtokens per second | Claude 4.1 Opus29 tok/s | GPT-5.3 Codex79 tok/s | GPT-5.3 Codex has the higher measured throughput. |
| First-answer latencyseconds to first token | Claude 4.1 Opus1.66 s | GPT-5.3 Codex88.26 s | Claude 4.1 Opus reaches the first token sooner. |
| Context windowmaximum listed tokens | Claude 4.1 Opus200K | GPT-5.3 Codex400K | GPT-5.3 Codex lists the larger context window. |
Benchmark Deep Dive
Agentic5 benchmarks
CodingClaude 4.1 Opus wins5 benchmarks
Reasoning2 benchmarks
Knowledge6 benchmarks
| Benchmark | Claude 4.1 Opus | GPT-5.3 Codex | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 28.2% | 44.3% | GPT-5.3 Codex leads |
| AA-GPQA DiamondSource | — | 91.5% | Not comparable |
| AA-HLESource | — | 39.9% | Not comparable |
| AA-Omniscience IndexSource | — | 9.9% | Not comparable |
| AA-Omniscience AccuracySource | — | 51.8% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 86.9% | Not comparable |
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude 4.1 Opus | GPT-5.3 Codex | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 75.4% | Not comparable |
Frequently Asked Questions (2)
Which is better, Claude 4.1 Opus or GPT-5.3 Codex?
GPT-5.3 Codex is ahead on BenchLM's BenchAlign leaderboard, 66.69 to 45.88. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 74.5% and 85%.
Which is better for coding, Claude 4.1 Opus or GPT-5.3 Codex?
Claude 4.1 Opus has the edge for coding in this comparison, averaging 74.5 versus 67.2. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
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