Claude Sonnet 5 vs Gemini 3.8 Flash: Specs & Benchmark Comparison
Claude Sonnet 5 is developed by Anthropic, while Gemini 3.8 Flash comes from Google. Claude Sonnet 5 was released in June 2026, and Gemini 3.8 Flash followed 3 months later in September 2026.
The two models share 4 published benchmarks. They split them evenly, 2 to 2. The widest gaps are on GDP.pdf, where Claude Sonnet 5 scores 81.6% against 35.0%; DeepSWE 1.1, where Gemini 3.8 Flash scores 73.7% against 54.0%. Averaged across everything we track, Claude Sonnet 5 sits at 58.4% and Gemini 3.8 Flash at 59.2%.
Gemini 3.8 Flash is the cheaper API at $0.75 per million input tokens and $3.75 per million output tokens, roughly 3 times cheaper than Claude Sonnet 5 at $2 and $10. Both accept a context window of about 1M tokens. Claude Sonnet 5 accepts text and images as input, while Gemini 3.8 Flash accepts text, images, audio, and video.
| Characteristic | Claude Sonnet 5 | Gemini 3.8 Flash |
|---|---|---|
| Company | Anthropic | |
| Release Date | June 30, 2026 | September 2, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 1.0M |
| Context (output) | 64K | 66K |
| Input Price / 1M | $2.00 | $0.75 |
| Output Price / 1M | $10.00 | $3.75 |
| Average Score | 58.4% | 59.2% |
| Benchmarks | ||
| GDP.pdf | 81.6% | 35.0% |
| DeepSWE 1.1 | 54.0% | 73.7% |
| Terminal-Bench 4.0 | 12.4% | 19.1% |
| CharXiv-R | 88.3% | 86.2% |
Visual Benchmark Comparison
Verdict
Gemini 3.8 Flash leads in 2 out of 4 comparison categories.
Both models show comparable average scores: Claude Sonnet 5 — 0.6, Gemini 3.8 Flash — 0.6.
Gemini 3.8 Flash is 2.7x cheaper: input $0.75/1M vs $2.00/1M tokens.
Same context size: 1M tokens.
Gemini 3.8 Flash is newer: released 9/2/2026 vs 6/30/2026.
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Frequently Asked Questions
Which is better for coding — Claude Sonnet 5 or Gemini 3.8 Flash?
Which model is cheaper — Claude Sonnet 5 or Gemini 3.8 Flash?
Which has a larger context window — Claude Sonnet 5 or Gemini 3.8 Flash?
The Claude Sonnet 5 and Gemini 3.8 Flash comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Claude Sonnet 5 or Gemini 3.8 Flash page. See also the complete list of AI model comparisons.