Claude Fable 5.1 vs Gemini 3.8 Flash
API pricing, context window and capabilities for Claude Fable 5.1 and Gemini 3.8 Flash, side by side. Prices are the cheapest listed serving route per 1M tokens, from LiteLLM and OpenRouter.
Verdict
computed from the published numbersClaude Fable 5.1 wins on Terminal-Bench and on intelligence. Gemini 3.8 Flash wins on price.
Price
Gemini 3.8 Flash
Terminal-Bench
Claude Fable 5.1
Intelligence
Claude Fable 5.1
Context window
Tied
Key takeaways
who wins on what, from the published numbersClaude Fable 5.1 wins
- Higher max output (128K vs 66K)
- More serving providers (7 vs 5)
Gemini 3.8 Flash wins
- Cheaper input ($10.00 vs $0.75 /1M)
- Cheaper output ($50.00 vs $3.75 /1M)
- Supports audio
Cheaper overall
Gemini 3.8 Flash
$0.75 + $3.75 /1M
Larger context
Tied
More providers
Claude Fable 5.1
7 providers
Pricing & specs
cheapest listed route · per 1M tokensOn-demand listed rates, OpenRouter routed quotes and Vercel reseller quotes. Enterprise commitments can be materially lower.
| Claude Fable 5.1 | Gemini 3.8 Flash | |
|---|---|---|
| Input $/1M | $10.00via Anthropic | $0.75via Google best |
| Output $/1M | $50.00via Anthropic | $3.75via Google best |
| Context window | 1M | 1M |
| Max output | 128K best | 66K |
| Serving providers | 7 best | 5 |
| Date | Released Sep 1, 2026 | Released Sep 2, 2026 |
Benchmarks
Benchmark scores, side by side| Claude Fable 5.1 | Gemini 3.8 Flash | |
|---|---|---|
| Intelligence | 53.4 best | 40.9 |
| Terminal-Bench | 91% best | 88% |
| GPQA Diamond | 94% | 95% best |
| Output speed | 71 t/s | 145 t/s best |
| Latency (TTFT) | 249.68s | 24.48s best |
Cost calculator
choose a serving route for each sideInput tokens / month
Output tokens / month
Claude Fable 5.1
via Amazon Bedrock
$100
Gemini 3.8 Flash
via Vertex AI
$7.50
Capabilities
feature support, side by side| Feature | Claude Fable 5.1 | Gemini 3.8 Flash |
|---|---|---|
| Vision | ✓ | ✓ |
| Tool use | ✓ | ✓ |
| Reasoning | ✓ | ✓ |
| Audio | — | ✓ |
| Prompt caching | ✓ | ✓ |
| Structured output | ✓ | ✓ |
| Web search | ✓ | ✓ |
Related comparisons
Frequently asked questions
Which is cheaper, Claude Fable 5.1 or Gemini 3.8 Flash?
Gemini 3.8 Flash is cheaper for input ($10.00 vs $0.75 per 1M tokens) from Google. Gemini 3.8 Flash is cheaper for output ($50.00 vs $3.75 per 1M tokens) from Google.
What is the context window difference between Claude Fable 5.1 and Gemini 3.8 Flash?
Both Claude Fable 5.1 and Gemini 3.8 Flash have about a 1M-token context window.
How do Claude Fable 5.1 and Gemini 3.8 Flash compare on benchmarks?
On the tracked benchmarks, Claude Fable 5.1 leads on Terminal-Bench, and Claude Fable 5.1 leads on intelligence.
Listed prices from LiteLLM, OpenRouter and Vercel · last checked Oct 14, 2026
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