Claude Opus 4.8 vs GPT-5.5
Anthropic against OpenAI, costed on the same three workloads. Claude Opus 4.8 is cheaper on all three workloads.
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Monthly bill, side by side
| Workload | Claude Opus 4.8 | GPT-5.5 | Difference |
|---|---|---|---|
| Support chatbot 2,500 six-turn conversations a day |
$20,138 | $22,163 | $2,025 (+10%) |
| Document summarizer 1,000 single-shot summaries a day |
$2,430 | $2,550 | $120 (+5%) |
| Coding agent 200 twelve-turn sessions a day |
$14,040 | $14,940 | $900 (+6%) |
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 Opus 4.8 | GPT-5.5 | |
|---|---|---|
| Input, per 1M tokens | $5 | $5 |
| Output, per 1M tokens | $25 | $30 |
| Cached input | $0.5 | $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 Opus 4.8 stops at 1M.
Run this comparison on your own numbers
Full detail: Claude Opus 4.8 pricing · GPT-5.5 pricing
More comparisons
Other head-to-heads that include Claude Opus 4.8 or GPT-5.5.
- Claude Opus 4.8 vs Gemini 3.1 Pro
- Claude Opus 4.8 vs GPT-5.6 Sol
- Claude Opus 4.8 vs GPT-5.6 Terra
- 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 Opus 4.8 or GPT-5.5?
Claude Opus 4.8 is cheaper on all three workloads.
How much would Claude Opus 4.8 and GPT-5.5 cost each month?
On PromptSpend's standard workloads, per month: support chatbot: Claude Opus 4.8 $20,138, GPT-5.5 $22,163 (Claude Opus 4.8 is cheaper by $2,025); document summarizer: Claude Opus 4.8 $2,430, GPT-5.5 $2,550 (Claude Opus 4.8 is cheaper by $120); coding agent: Claude Opus 4.8 $14,040, GPT-5.5 $14,940 (Claude Opus 4.8 is cheaper by $900). No prompt caching and no batch discount is assumed.
How do Claude Opus 4.8 and GPT-5.5 differ apart from price?
GPT-5.5 reads up to 1.05M tokens of context in one request; Claude Opus 4.8 stops at 1M.