Model comparison
Claude Haiku 5.5 vs GPT-5.1-Codex-mini
Claude Haiku 5.5 has enough public results to be ranked (#52); GPT-5.1-Codex-mini does not yet, so treat this comparison as directional.
Last verified . 1 shared benchmarks.
Summary
- They share 1 benchmark with published results for both. Claude Haiku 5.5 scores higher in 1 category and GPT-5.1-Codex-mini in 0 categories; one gap is clear of the uncertainty.
- The widest gap is in coding, where Claude Haiku 5.5 leads 49.2 to 31.6.
- Claude Haiku 5.5 is cheaper at $0.10 / $0.50 per million input/output tokens, against $0.25 / $2 for GPT-5.1-Codex-mini.
- Claude Haiku 5.5 accepts more context: 1M tokens versus 400K.
Side by side
| Claude Haiku 5.5 | GPT-5.1-Codex-mini | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 49.5 | 37.3 |
| Released | 2026-10-07 | 2025-11-12 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 400K |
| Max output | 128K | 128K |
| Input $ / M tokens | $0.10 | $0.25 |
| Output $ / M tokens | $0.50 | $2 |
| Results tracked | 9 | 2 |
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Category by category
Coding Claude Haiku 5.5 leads
Claude Haiku 5.5: 49.2 (#50), GPT-5.1-Codex-mini: 31.6
| Benchmark | Claude Haiku 5.5 | GPT-5.1-Codex-mini |
|---|---|---|
| LMArena WebDev | 1587 | 1244 |
Agentic & Tool Use Not comparable
Claude Haiku 5.5: —, GPT-5.1-Codex-mini: 38.5
| Benchmark | Claude Haiku 5.5 | GPT-5.1-Codex-mini |
|---|---|---|
| Terminal-Bench | — | 61.6% |
Reasoning Not comparable
Claude Haiku 5.5: 35.2 (#69), GPT-5.1-Codex-mini: —
| Benchmark | Claude Haiku 5.5 | GPT-5.1-Codex-mini |
|---|---|---|
| NYT Connections (extended) | 65.7% | — |
| Mystery Game Puzzles | 30% | — |
Math Not comparable
Claude Haiku 5.5: 73.6 (#18), GPT-5.1-Codex-mini: —
| Benchmark | Claude Haiku 5.5 | GPT-5.1-Codex-mini |
|---|---|---|
| FrontierMath (Tiers 1-3) | 75.1% | — |
| FrontierMath Tier 4 | 46.3% | — |
| OTIS Mock AIME 2024-2025 | 98.9% | — |
Knowledge Not comparable
Claude Haiku 5.5: 50.8 (#70), GPT-5.1-Codex-mini: —
| Benchmark | Claude Haiku 5.5 | GPT-5.1-Codex-mini |
|---|---|---|
| GPQA Diamond | 89.6% | — |
| SimpleQA Verified | 23.8% | — |
Multimodal Not comparable
Claude Haiku 5.5: 43.7 (#21), GPT-5.1-Codex-mini: —
| Benchmark | Claude Haiku 5.5 | GPT-5.1-Codex-mini |
|---|---|---|
| Furniture Assembly | 47.5% | — |
Frequently asked questions
Is Claude Haiku 5.5 better than GPT-5.1-Codex-mini?
Claude Haiku 5.5 has enough public results to be ranked (#52); GPT-5.1-Codex-mini does not yet, so treat this comparison as directional.
Which is cheaper, Claude Haiku 5.5 or GPT-5.1-Codex-mini?
Claude Haiku 5.5 is cheaper. It lists at $0.10 per million input tokens and $0.50 per million output tokens; GPT-5.1-Codex-mini lists at $0.25 and $2.
Is Claude Haiku 5.5 or GPT-5.1-Codex-mini better for coding?
Claude Haiku 5.5 scores higher on coding benchmarks: 49.2 versus 31.6 in the Noometry coding category.
Which has the bigger context window?
Claude Haiku 5.5 does, with 1M tokens against 400K.
How many benchmarks do Claude Haiku 5.5 and GPT-5.1-Codex-mini share?
1 benchmark has published results for both models. Claude Haiku 5.5 has 9 scored results on Noometry and GPT-5.1-Codex-mini has 2.