text model comparison
Claude Fable 5.1 vs Granite 4.2 30B
Claude Fable 5.1 and Granite 4.2 30B are both current text models, from Anthropic and IBM. On Arena Text, Claude Fable 5.1 scores 1501 Elo and Granite 4.2 30B 1340 Elo (Arena, measured October 8, 2026). Claude Fable 5.1 has the larger context window, 1,000,000 vs 128,000 tokens.
Data verified October 13, 2026 · Dataset 2026-10-13
Side by side
Standard-tier prices in effect today. The better value in each row is highlighted.
| Fact | Claude Fable 5.1 | Granite 4.2 30B |
|---|---|---|
| Price per 1M input tokens | $10 | Not reported |
| Price per 1M output tokens | $50 | Not reported |
| Arena Text | 1501 Elo (#4 of 49) (better) | 1340 Elo (#48 of 49) |
| FrontierMath Tiers 1-3 (v2) | 90.2% (#4 of 40) | Not measured |
| SimpleQA Verified | 70.8% (#5 of 36) | Not measured |
| Provider | Anthropic | IBM |
| Release date | September 1, 2026 | August 25, 2026 |
| Access | API only | open weights |
| Context window | 1,000,000 tokens | 128,000 tokens |
| Max output | 128,000 tokens | Not reported |
| Input | text, image | text |
| Output | text | text |
When to choose each
Claude Fable 5.1
Best for
- Long-horizon agentic coding where a large prompt prefix is replayed across many turns
- Work where Claude Opus 5 at higher effort has already been evaluated and fell short
Watch out for
- Base input and output pricing is unchanged from Fable 5 at $10 / $50; the saving is entirely in cache reads, so a workload with little cache reuse sees no discount
- The 4.7-generation tokenizer produces roughly 30% more tokens for the same text than Claude Sonnet 4.6 and earlier, so per-token rates are not directly comparable across generations
- Anthropic’s launch comparisons are self-reported and were not reproduced independently here
Granite 4.2 30B
Best for
- Self-hosted enterprise agents that need a permissive licence
Watch out for
- IBM says it is fine-tuned mainly on English instruction data, so other languages may be weaker
- IBM publishes no per-token API price for Granite 4.2
Claude Fable 5.1 vs Granite 4.2 30B FAQ
Which scores higher on independent benchmarks, Claude Fable 5.1 or Granite 4.2 30B?
Claude Fable 5.1 leads on Arena Text, 1501 Elo to 1340 Elo. Scores are independent evaluations, not either vendor's launch figures.
Which has the larger context window, Claude Fable 5.1 or Granite 4.2 30B?
Claude Fable 5.1 has the larger context window, 1,000,000 vs 128,000 tokens.
Can I run Claude Fable 5.1 or Granite 4.2 30B myself?
Granite 4.2 30B is released as open weights you can run yourself; Claude Fable 5.1 is available through its provider's API only.
Related comparisons
Production evaluation
Choosing between Claude Fable 5.1 and Granite 4.2 30B?
Public benchmarks narrow the shortlist. We run both on your own tasks, data and cost limits, then build the routing and review controls to run the winner in production.
- A head-to-head evaluation on your real workload
- Routing between models by cost and difficulty