Claude Sonnet 5 vs Gemini 3.8 Flash
Claude Sonnet 5 costs $2.00 / $10.00 and Gemini 3.8 Flash costs $0.75 / $3.75 per million input / output tokens. At a typical 3:1 mix, Gemini 3.8 Flash is 2.7× cheaper than Claude Sonnet 5.
Claude Sonnet 5
Anthropic
Input
$2.00
per 1M
Output
$10.00
per 1M
Cached
$0.20
1M context
Input
$0.75
per 1M
Output
$3.75
per 1M
Cached
$0.075
1M context
Side by side
Green marks the cheaper price, larger context window, bigger discount or higher score.
| Detail | Claude Sonnet 5 | Gemini 3.8 Flash |
|---|---|---|
| Input per 1M | $2.00 | $0.75 |
| Output per 1M | $10.00 | $3.75 |
| Blended per 1M (3:1) | $4.00 | $1.50 |
| Cached input per 1M | $0.20 | $0.075 |
| Batch or off-peak discount | 50% (batch) | 50% (batch) |
| Long prompts | Same rate at any length | Same rate at any length |
| Context window | 1M | 1M |
| Released | 30 Jun 2026 | 2 Sep 2026 |
| Open weights | No | No |
| Arena text score | — | 1492 |
| Verified | 27 Sep 2026 | 27 Sep 2026 |
Sources: Anthropic pricing and Gemini API pricing.
Monthly cost on three workloads
List prices, no batch discount. The cached share applies where a model has a cache rate.
| Workload | Claude Sonnet 5 | Gemini 3.8 Flash | Difference |
|---|---|---|---|
| Customer chat assistant50,000 conversations a month, about 2,000 tokens in and 400 out each; 50% cached | $310 | $116 | $194 |
| Document Q&A (RAG)20,000 questions a month over retrieved documents, 12,000 in and 600 out; 30% cached | $470 | $176 | $294 |
| Coding agent400 tasks a month, 40 steps each with a growing context; 85% cached | $433 | $162 | $270 |
How they differ
- Gemini 3.8 Flash is cheaper on input ($0.75 vs $2).
- Gemini 3.8 Flash is cheaper on output ($3.75 vs $10), which matters most for long answers and reasoning models.
- Gemini 3.8 Flash accepts longer prompts (1M vs 1M tokens).
- Cached input is cheaper on Gemini 3.8 Flash ($0.075 vs $0.20), which favours agents and chat apps that resend the same context.
Recent changes
All changes- Google launched Gemini 3.8 Flash at $0.75 / $3.75 until 31 December, then $1.50 / $7.50.
- Google launched Gemini 3.7 Flash at $0.75 / $3.75.
- ▼ 50%Google launched Gemini 3.6 Flash at $0.75 / $3.75, half the price of 3.5 Flash, and Gemini 3.5 Flash-Lite at $0.30 / $2.50.
- ▼ 33%Anthropic launched Claude Sonnet 5 at $2 / $10, cheaper than Sonnet 4.6's $3 / $15.
- Anthropic retired Claude Opus 4 and Claude Sonnet 4.
