Claude Sonnet vs GPT
Claude Sonnet 5.5 vs GPT-6.1 Sol
Claude Sonnet 5.5 (Anthropic) and GPT-6.1 Sol (OpenAI) compared on the facts each vendor publishes. Price does not decide it: both list $2 in and $10 out per 1M tokens. For very long inputs, GPT-6.1 Sol lists the larger context window: 1.05M tokens against 1M. We have not run either model: every value below is Reported, with a link to its source.
Reported Updated · Markdown · All model comparisons
Anthropic · generally available · API only · released Sep 28, 2026
- $ in / 1M tokens
- $2
- $ out / 1M tokens
- $10
- Context
- 1M
- Max output
- —
OpenAI · generally available · API only · released Sep 29, 2026
- $ in / 1M tokens
- $2
- $ out / 1M tokens
- $10
- Context
- 1.05M
- Max output
- 128K
How to choose
- Price does not decide it: both list $2 in and $10 out per 1M tokens.
- For very long inputs, GPT-6.1 Sol lists the larger context window: 1.05M tokens against 1M.
- GPT-6.1 Sol is newer, by 1 day.
Specs side by side
Each value is read from the vendor page linked beside it. “Not published” means we found no vendor figure, not that the feature is missing.
| Spec | Claude Sonnet 5.5 | GPT-6.1 Sol |
|---|---|---|
| Price (as listed) | $2 in / $10 out per 1M tokenssource | $2 in / $10 out per 1M tokenssource |
| Context window | 1,000,000 tokens (1M)source | 1,050,000 tokens (1.05M)source |
| Max output | Not published | 128,000 tokenssource |
| Input | text, imagesource | text, imagesource |
| Output | textsource | textsource |
| Licence | Proprietary (API)source | Proprietary (API)source |
| Released | Sep 28, 2026source | Sep 29, 2026source |
| Status | generally available | generally available |
| API id | claude-sonnet-5-5source | gpt-6.1-solsource |
Benchmark snapshots
From the boards named below, not our tests. Boards use different tasks and settings, so compare within a row, never across rows.
| Board | Claude Sonnet 5.5 | GPT-6.1 Sol | Type, date |
|---|---|---|---|
| LMArena WebDev leaderboard (Elo-style score) | 1769 (Claude Sonnet 5.5 (xHigh)); 1709 (Claude Sonnet 5.5 (High)) | 1749 | Independent, Oct 22, 2026 |
| Terminal-Bench 4.0 official leaderboard | 61.8% | 58.2% | Independent, Oct 26, 2026 |
| SWE-bench Pro (Public), as reported by the vendors | 81.3% | not listed | Vendor-reported, Oct 26, 2026 |
| Artificial Analysis: Kimi K3.1 Pro launch benchmarks (Terminal-Bench 4.0) | 64% | not listed | Independent, Oct 23, 2026 |
More context: best LLM for coding.
FAQ
Which is cheaper, Claude Sonnet 5.5 or GPT-6.1 Sol?
Claude Sonnet 5.5: $2 in / $10 out per 1M tokens. GPT-6.1 Sol: $2 in / $10 out per 1M tokens. Both prices are the vendors' own listed prices on the date each model was last verified.
Which has the bigger context window?
GPT-6.1 Sol, with 1,050,000 tokens against 1,000,000.
Which is better for coding?
We have not tested either. Sourced snapshots: LMArena WebDev leaderboard (Elo-style score) (independent, Oct 22, 2026): Claude Sonnet 5.5 (xHigh) 1769, GPT-6.1 Sol (Max) 1749, Claude Sonnet 5.5 (High) 1709; Terminal-Bench 4.0 official leaderboard (independent, Oct 26, 2026): Claude Sonnet 5.5 (Claude Code, max) 61.8%, GPT-6.1 Sol (Codex, max) 58.2%; SWE-bench Pro (Public), as reported by the vendors (vendor-reported, Oct 26, 2026): Claude Sonnet 5.5 (max) 81.3%; Artificial Analysis: Kimi K3.1 Pro launch benchmarks (Terminal-Bench 4.0) (independent, Oct 23, 2026): Claude Sonnet 5.5 64%. Scores from different boards are not comparable with each other.
Are Claude Sonnet 5.5 and GPT-6.1 Sol open source?
Claude Sonnet 5.5: Proprietary (API), no downloadable weights. GPT-6.1 Sol: Proprietary (API), no downloadable weights.
Did you test Claude Sonnet 5.5 and GPT-6.1 Sol?
No. This page is Reported: every fact is read from the vendor page linked beside it, and benchmark numbers come from the named boards.
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