Claude Sonnet 5 vs GPT-5.5
Anthropic against OpenAI, costed on the same three workloads. Claude Sonnet 5 is cheaper on all three workloads.
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Monthly bill, side by side
| Workload | Claude Sonnet 5 | GPT-5.5 | Difference |
|---|---|---|---|
| Support chatbot 2,500 six-turn conversations a day |
$8,055 | $22,163 | $14,108 (2.8×) |
| Document summarizer 1,000 single-shot summaries a day |
$972 | $2,550 | $1,578 (2.6×) |
| Coding agent 200 twelve-turn sessions a day |
$5,616 | $14,940 | $9,324 (2.7×) |
No prompt caching and no batch discount on either side, so the comparison is like for like. Both figures assume 30 days a month.
The rate cards
| Claude Sonnet 5 | GPT-5.5 | |
|---|---|---|
| Input, per 1M tokens | $2 | $5 |
| Output, per 1M tokens | $10 | $30 |
| Cached input | $0.2 | $0.5 |
| Context window | 1M | 1.05M |
| Maximum output | 128K | 128K |
| Reasoning model | yes | yes |
| Vision | yes | yes |
Beyond the price
- GPT-5.5 reads up to 1.05M tokens of context in one request; Claude Sonnet 5 stops at 1M.
Run this comparison on your own numbers
Full detail: Claude Sonnet 5 pricing · GPT-5.5 pricing
More comparisons
Other head-to-heads that include Claude Sonnet 5 or GPT-5.5.
- Claude Sonnet 5 vs Gemini 3.1 Pro
- Claude Sonnet 5 vs Gemini 3.7 Flash
- Claude Sonnet 5 vs Gemini 4 Argon
- GPT-5.5 vs Claude Fable 5
- GPT-5.5 vs Claude Opus 4.6
- GPT-5.5 vs Claude Opus 4.7
Common questions
Which is cheaper, Claude Sonnet 5 or GPT-5.5?
Claude Sonnet 5 is cheaper on all three workloads.
How much would Claude Sonnet 5 and GPT-5.5 cost each month?
On PromptSpend's standard workloads, per month: support chatbot: Claude Sonnet 5 $8,055, GPT-5.5 $22,163 (Claude Sonnet 5 is cheaper by $14,108); document summarizer: Claude Sonnet 5 $972, GPT-5.5 $2,550 (Claude Sonnet 5 is cheaper by $1,578); coding agent: Claude Sonnet 5 $5,616, GPT-5.5 $14,940 (Claude Sonnet 5 is cheaper by $9,324). No prompt caching and no batch discount is assumed.
How do Claude Sonnet 5 and GPT-5.5 differ apart from price?
GPT-5.5 reads up to 1.05M tokens of context in one request; Claude Sonnet 5 stops at 1M.