# GPT-5.1-Codex vs GPT-5 (high)

> Side-by-side benchmark comparison for GPT-5.1-Codex and GPT-5 (high) across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-1-codex-vs-gpt-5-high
- Last updated: September 4, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: GPT-5.1-Codex and GPT-5 (high) share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- GPT-5.1-Codex has the larger published context window at 400K.

## Model Snapshot

| Property | GPT-5.1-Codex | GPT-5 (high) |
|----------|----------|----------|
| Creator | OpenAI | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 400K | 128K |
| Independent public score (not head-to-head) | 51.62 | 58.03 |
| Benchmarks Covered | 3 | 2 |
| Pricing (input/output) | $1.25 / $10.00 | $1.25 / $10.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GPT-5.1-Codex public-lane score: 51.4 (Estimated · #54/151)
- GPT-5 (high) public-lane score: 51.1 (Estimated · #59/151)

| Benchmark | GPT-5.1-Codex | GPT-5 (high) | Winner |
|-----------|-----------|-----------|--------|
| Gert Labs | 49.68% | Coming soon | Coming soon |
| JobBench | 26.2% | 8.5% | GPT-5.1-Codex |

### Coding

- Winner: Insufficient shared evidence
- GPT-5.1-Codex public-lane score: 47.4 (Estimated · #89/183)
- GPT-5 (high) public-lane score: Coming soon

| Benchmark | GPT-5.1-Codex | GPT-5 (high) | Winner |
|-----------|-----------|-----------|--------|
| Vibe Code Bench | 13.12% | 20.09% | GPT-5 (high) |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- GPT-5.1-Codex public-lane score: 66.8 (Unranked · 1 rankable row)
- GPT-5 (high) public-lane score: Coming soon

### Reasoning

- Winner: Insufficient shared evidence
- GPT-5.1-Codex public-lane score: 70.6 (Unranked · 2 rankable rows)
- GPT-5 (high) public-lane score: Coming soon

### Knowledge

- Winner: Insufficient shared evidence
- GPT-5.1-Codex public-lane score: 53.3 (Estimated · #69/181)
- GPT-5 (high) public-lane score: Coming soon

### Instruction Following

- Winner: Insufficient shared evidence
- GPT-5.1-Codex public-lane score: 85.3 (#42/120)
- GPT-5 (high) public-lane score: Coming soon

## FAQ

### Is there enough evidence to pick between GPT-5.1-Codex and GPT-5 (high)?

Not yet. The models share only 2 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [GPT-5.1-Codex vs GPT-5 (medium)](/compare/gpt-5-1-codex-vs-gpt-5-medium)
- [GPT-5 (high) vs GPT-5 (medium)](/compare/gpt-5-high-vs-gpt-5-medium)
- [GPT-5.1-Codex vs GPT-5 mini](/compare/gpt-5-1-codex-vs-gpt-5-mini)
- [GPT-5 (high) vs GPT-5 mini](/compare/gpt-5-high-vs-gpt-5-mini)

## Explore More

- [GPT-5.1-Codex profile](/models/gpt-5-1-codex)
- [GPT-5 (high) profile](/models/gpt-5-high)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)