Claude Sonnet 5.5 vs GPT-6.1 Sol
Two models at exactly the same list price ($2 in / $10 out per million tokens), from Anthropic and OpenAI, released one day apart. GPT-6.1 Sol vs Claude Sonnet 5.5 in one table: list price, context window, output limit, cutoff and release date, with a cost calculator for your own monthly volume.
| Spec | Claude Sonnet 5.5 | GPT-6.1 Sol |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Released | 2026-09-28 | 2026-09-29 |
| Input / 1M tokens | $2.00 | $2.00 |
| Output / 1M tokens | $10.00 | $10.00 |
| Cached input / 1M | $0.100 | $0.100 |
| Batch input / output | $1.00 / $5.00 | $1.00 / $5.00 |
| Context window | 1M | 1.05M |
| Max output | 128K | 128K |
| Knowledge cutoff | 2026-06 | 2026-04-30 |
| Image input | yes | yes |
| API ID | claude-sonnet-5-5 | gpt-6.1-sol |
| Status | Generally available | Generally available |
Cost at your volume
list price, per monthPaste your usage instead of typing
Paste a line from a provider invoice, a usage dashboard, or an API response. We look for input and output token counts (JSON keys like input_tokens, prompt_tokens, completion_tokens, or text like "1.2M in, 300k out"). Nothing leaves your browser.
Examples that work: {"usage":{"input_tokens":1200000,"output_tokens":300000}} · 1.2M in, 300k out · GPT-6.1 Sol: 2.4B input tokens, 310M output tokens
Same token counts on both sides. Real bills differ: tokenizers differ, reasoning models bill thinking tokens as output, and caching or batch discounts apply differently. Rank all models →
Pick Sonnet 5.5 if…
- You want the later knowledge cutoff (2026-06 vs 2026-04-30).
- You are already on Anthropic's stack (Claude.ai (all plans), Claude Code, Claude API).
- Output generation 30%+ faster than Sonnet 5; up to 30% lower cost per task (vendor claims).
Pick GPT-6.1 Sol if…
- You need the larger context window (1.05M tokens).
- You are already on OpenAI's stack (ChatGPT Work (Plus, Pro, Business, Enterprise, Edu), Codex, OpenAI API).
- OpenAI positions it as close to GPT-6 Astra on agentic coding, computer use and professional work at 1/5 the token price (vendor claim).
Price difference, in words
Both list at exactly $2.00 in / $10.00 out per million tokens, so a job that uses one million tokens each way costs $12.00 on either. The differences are elsewhere: cached-input price ($0.100 vs $0.100), context window, and what each vendor claims about quality.
With prompt caching, the gap moves: cached input is $0.100 on Sonnet 5.5 and $0.100 on GPT-6.1 Sol. Agent loops that re-send a large system prompt every turn pay mostly cached-input rates.
- Claude Sonnet 5.5 model page (platform.claude.com) read 2026-10-08
release date, model IDs, context, output, pricing, cutoff - Anthropic pricing page read 2026-10-08
cache, batch prices - Anthropic announcement: Claude Sonnet 5.5 read 2026-10-08
benchmarks (vendor-reported), speed and cost claims
- OpenAI model page: gpt-6.1-sol read 2026-10-08
context, max output, cutoff, pricing, features, endpoints - OpenAI API pricing read 2026-10-08
standard, batch, flex, fast, long-context rates - OpenAI API changelog (Sep 29, 2026 entry) read 2026-10-08
release date, multi-agent beta - AWS What's New: GPT-6.1 Sol on Amazon Bedrock read 2026-10-08
Bedrock availability - TechCrunch: OpenAI launches GPT-6.1 Sol (secondary; quotes OpenAI) read 2026-10-08
availability by tier, OpenAI's capability claims