Claude Sonnet 5 vs GPT-5
GPT-5 is cheaper for every workload modelled here.
List prices checked
Specifications and rates
| Property | Claude Sonnet 5 | GPT-5 |
|---|---|---|
| Input per 1M | $3.00 | $1.25 |
| Output per 1M | $15.00 | $10.00 |
| Cached input per 1M | $0.300 | $0.125 |
| Blended (3:1) | $6.00 | $3.44 |
| Context window | 200K | 400K |
| Max output | 64K | 128K |
| Inputs accepted | text, image | text, image |
Source: Anthropic pricing (August 2026) · OpenAI pricing (May 2026). Published list prices only — committed-use discounts, regional variation, and per-request charges are not included. Not yet independently re-checked against the vendor’s page.
Monthly cost by workload
Identical token volumes through both rate cards. Output-heavy profiles are where the ranking flips.
| Workload | Claude Sonnet 5 | GPT-5 | Cheaper |
|---|---|---|---|
| In-app chat assistantA support or help assistant handling a few thousand conversations a month, with short prompts and short answers. | $135 | $75 | GPT-5saves $60/mo (44%) |
| RAG over documentsRetrieval-augmented answering where each request stuffs several retrieved passages into the prompt, so input dominates. | $1,125 | $525 | GPT-5saves $600/mo (53%) |
| Coding agentAn agentic loop that reads files and writes patches, generating heavy output and re-sending large context on every turn. | $2,700 | $1,500 | GPT-5saves $1,200/mo (44%) |
What each one is for
Claude Sonnet 5
by Anthropic
The workhorse of the Claude family and the default for production work at volume. Introductory pricing of $2/$10 per million tokens runs to 31 August 2026; the $3/$15 standard rate shown here is what applies after that.
GPT-5
by OpenAI
OpenAI's flagship, priced aggressively below the other frontier models on input and with a 90% cached-input discount that makes long system prompts nearly free to reuse.
Common questions
- Is Claude Sonnet 5 or GPT-5 cheaper in 2026?
- GPT-5, for every workload modelled here. On a blended 3:1 basis it costs $3.44 per million tokens against Claude Sonnet 5's $6.00.
- Which has the larger context window?
- GPT-5, at 400K tokens against 200K. A larger window only helps if you can afford to fill it — the cost of one full-context request is in the table above.
- Which is cheaper for output-heavy work like agents?
- GPT-5, at $10.00 per million output tokens against $15.00. Reasoning tokens bill as output, so for agentic loops this axis usually decides the invoice regardless of what the input rates look like.
- What is not included in these figures?
- Batch-processing discounts, fine-tuning, long-context surcharges above a provider's standard tier, and any enterprise agreement. These are published pay-as-you-go list prices, checked against each provider's own pricing page on the date shown.
- Is switching from Claude Sonnet 5 to GPT-5 worth it?
- On price alone it is about 43% cheaper on a blended basis. Whether that survives contact with your workload depends on output quality and on retry rate — a cheaper model that needs two attempts is not cheaper. Model the specific volumes in the calculator before you migrate.