Claude Fable 5.2 vs Gemini 3.8 Flash
Gemini 3.8 Flash is 10.7x cheaper than Claude Fable 5.2 on our example workload, at list prices.
Side by side
| Measure | Claude Fable 5.2 | Gemini 3.8 Flash |
|---|---|---|
| Provider | Anthropic | |
| Input / 1M tokens | $8.00 | $0.750 |
| Output / 1M tokens | $40.00 | $3.75 |
| Output price ÷ input price | 5.0x | 5.0x |
| Blended / 1M (3:1) | $16.00 | $1.50 |
| Context window | 1M | 1M |
| ≈ English words that fit | 750,000 | 750,000 |
| 1,000 calls (2000+500 tok) | $36.00 | $3.38 |
| AA Intelligence Index | 65 | 31 |
| LMArena Text | Not on LMArena yet | 1497 |
| Blended $ per AA index point | $0.246 | $0.048 |
List prices from official pages (Anthropic, Google), verified 2026-11-10. Benchmarks from public leaderboards (Artificial Analysis, LMArena), not run by us. Word counts use the rough 0.75 words per token rule for English. "$ per index point" is our own arithmetic (blended price ÷ index score), a rough value-for-money signal, not a benchmark.
What real workloads cost
Four example request shapes, priced at list rates with no caching or batch discounts. Monthly figures assume 100,000 requests.
| Workload | Claude Fable 5.2 | Gemini 3.8 Flash | Gap |
|---|---|---|---|
| Support chat reply a short system prompt, recent chat history and a reply | $0.0360 each $3,600.00 / mo | $0.00337 each $337.50 / mo | 10.7x |
| RAG answer a question plus about 20K tokens of retrieved documents, and a cited answer | $0.1920 each $19,200.00 / mo | $0.0180 each $1,800.00 / mo | 10.7x |
| 10-step agent task an agent loop of 10 model calls, each re-reading about 8K tokens of context and emitting a 400-token tool call | $0.8000 each $80,000.00 / mo | $0.0750 each $7,500.00 / mo | 10.7x |
| Long-report summary one 200K-token document summarized into about 2K tokens | $1.68 each $168,000.00 / mo | $0.1575 each $15,750.00 / mo | 10.7x |
When to pick each
- Pick Gemini 3.8 Flash when cost is the main constraint: at list prices it is 10.7x cheaper than Claude Fable 5.2 on a typical 2,000-in / 500-out call ($3.38 vs $36.00 per 1,000 calls).
- Pick Claude Fable 5.2 when answer quality matters more than price: it scores 65 vs 31 on the Artificial Analysis Intelligence Index, and costs 10.7x more per call.
- They come from different providers (Anthropic and Google), so switching means a second API key, SDK and billing account, and tool-calling formats differ. Our schema converter outputs both formats from one JSON Schema.
Context and pricing limits
- Claude Fable 5.2: 1M tokens of context. Gemini 3.8 Flash: 1M. Same size.
- Gemini 3.8 Flash: Promo price through Dec 31, 2026; $1.50/$7.50 from Jan 1, 2027. The prices above are this tier; check the official pricing page before committing.
- Cached input, batch and off-peak discounts can cut real bills a lot and differ by provider; they are not included here.
FAQ
Is Gemini 3.8 Flash cheaper than Claude Fable 5.2?
Yes, on our 2000-in / 500-out example call it costs $0.00337 vs $0.0360, 10.7x less.
Which has the larger context window?
Neither: both accept 1M tokens.
Which scores higher on benchmarks?
Claude Fable 5.2 scores 65 vs 31 on the Artificial Analysis Intelligence Index. LMArena Text: Claude Fable 5.2 not on LMArena yet, Gemini 3.8 Flash 1497. Benchmarks are averages; test both on your own prompts.
Run your own numbers in the token cost estimator · Claude Fable 5.2 pricing · Gemini 3.8 Flash pricing · All comparisons