AiGanakClaude Sonnet 5.5 vs Gemini 3.8 Flash: API pricing
Gemini 3.8 Flash is cheaper: a typical support answer costs $0.00367 against $0.00940 on Claude Sonnet 5.5 at list prices checked 26 October 2026. Gemini 3.8 Flash rises to $1.50 / $7.50 per million tokens on 1 January 2027, which makes the same answer $0.00735.
Claude Sonnet 5.5: $2 input / $10 output per 1M tokens. Gemini 3.8 Flash: $0.75 / $3.75.
Prices side by side
Sources: Anthropic, Google, checked 26 October 2026. Full details: Claude Sonnet 5.5 · Gemini 3.8 Flash.
| Claude Sonnet 5.5 | Gemini 3.8 Flash | |
|---|---|---|
| Input | $2 | $0.75 |
| Cached input | $0.1 | $0.075 |
| Output | $10 | $3.75 |
| Batch input / output | $1 / $5 | $0.375 / $1.88 |
| Cache write | $2.50 | not charged separately |
| Long prompts | No long-prompt surcharge listed | No long-prompt surcharge listed |
| Announced change | None announced | $1.50 / $7.50 from 1 January 2027 |
Cost per request
Token counts are stated so you can check the arithmetic.
| Task | Tokens | Claude Sonnet 5.5 | Gemini 3.8 Flash |
|---|---|---|---|
| Chat reply | 2,000 input tokens, none cached, 300-token reply | $0.00700 | $0.00263 |
| Support answer | 6,000 input tokens (4,000 cached instructions and help text), 500-token answer | $0.00940 | $0.00367 |
| Document summary | 20,000-token document, no caching, 800-token summary | $0.048 | $0.018 |
Monthly cost of support answers
| Answers per month | Claude Sonnet 5.5 | Gemini 3.8 Flash | Difference |
|---|---|---|---|
| 10,000 | $94.00 | $36.75 | $57.25 |
| 100,000 | $940 | $368 | $573 |
| 1,000,000 | $9,400 | $3,675 | $5,725 |
Price per token is only part of the story: the model that answers in fewer tokens, or needs fewer retries, can be cheaper in practice. Test both on your own requests before switching.
Claude Sonnet 5.5 vs Gemini 3.8 Flash: pricing questions
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Is Claude Sonnet 5.5 cheaper than Gemini 3.8 Flash?
Gemini 3.8 Flash is cheaper: a typical support answer costs $0.00367 against $0.00940 on Claude Sonnet 5.5 at list prices checked 26 October 2026. Gemini 3.8 Flash rises to $1.50 / $7.50 per million tokens on 1 January 2027, which makes the same answer $0.00735.
How much more does Claude Sonnet 5.5 cost than Gemini 3.8 Flash?
For a support answer with 6,000 input tokens (4,000 cached) and a 500-token reply, Claude Sonnet 5.5 costs 2.6× more than Gemini 3.8 Flash: $9.40 against $3.67 per 1,000 answers.
What do Claude Sonnet 5.5 and Gemini 3.8 Flash cost with batch processing?
Batch prices per million tokens: Claude Sonnet 5.5 $1 input / $5 output, Gemini 3.8 Flash $0.375 / $1.88. Batch requests return within 24 hours.
Should I switch from Claude Sonnet 5.5 to Gemini 3.8 Flash?
Only if quality holds on your own examples. Price per token is one factor; how many tokens each model uses for your task, and how often its answers need a retry, decide the real cost. Test both on 50 to 100 real requests before switching.
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