Claude Sonnet 4.6 vs GPT-5.4: cost compared

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GPT-5.4 is 17% cheaper on input and 0% cheaper on output than Claude Sonnet 4.6. Whether that makes it the right choice depends entirely on whether it does your task well enough — this page gives you the cost side of that trade, precisely.

Rates side by side

$ per million tokensClaude Sonnet 4.6GPT-5.4
Input$3.00$2.50
Output$15.00$15.00
Cached input$0.30$0.25
Batch input$1.50
Output : input ratio5.0×6.0×

What the difference is worth

Monthly cost for the same workload on each, without caching:

WorkloadClaude Sonnet 4.6GPT-5.4Difference
Support chatbot
1,000 conversations/month · 2,000 in + 500 out each
$13.50$12.50$1.00 saved
RAG search
10,000 queries/month · 8,000 in + 400 out each
$300$260$40.00 saved
Bulk extraction
10,000 documents · 3,000 in + 300 out each
$135$120$15.00 saved
Coding agent
100 runs/month · 400,000 in + 20,000 out each
$150$130$20.00 saved

Which to use

GPT-5.4 if the task is well-specified and mechanical — extraction, classification, formatting, routine transformation. The saving is real and compounds with volume.

Claude Sonnet 4.6 if the task involves genuine reasoning, long-horizon planning, or work where a wrong answer is expensive to catch. Paying 1.2× more on input is trivial compared to the cost of shipping a bad result.

These are different providers, so switching means a different SDK and a different tokenizer. The same text is a different number of tokens on each, so the price difference above is approximate at the margin. Measure token counts on your real inputs before committing.

Don't skip caching

Cached input costs $0.30 on Claude Sonnet 4.6 and $0.25 on GPT-5.4. If your prompts share a stable prefix, caching on the more expensive model can beat switching to the cheaper one outright — worth checking before you migrate anything.

Sources

Anthropic rates verified 2026-08-05 (source). OpenAI rates verified 2026-08-05 (source).