Claude Fable 5 vs Tri-21B-Think
Wins 5 of 5 areas
Coding · Reasoning · Facts · Long documents · Following instructions
Wins 0 of 5 areas
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Claude Fable 5 is the stronger all-rounder.
Scores updated · 11 tests both models report · How we compare
Where each one wins
Tests won in each of the five areas where both have results. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
- ReasoningHard problems that need careful thinking30Claude Fable 53 of 3 tests
- FactsGetting facts right instead of making them up20Claude Fable 52 of 2 tests
- CodingWriting and fixing software10Claude Fable 51 of 1 test
- Long documentsFinding answers in very long texts10Claude Fable 51 of 1 test
- Following instructionsDoing exactly what it is asked10Claude Fable 51 of 1 test
Coding, long documents and following instructions rest on a single test each.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
The biggest differences
The tests each model wins by the widest margin, up to three each. Scores are out of 100.
Where Claude Fable 5 pulls ahead
- Reasons across sets of long documentsAA-LCR+66.6points ahead
- Hard command-line tasks in a real terminalTerminal-Bench Hard+62.1points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+53.1points ahead
Where Tri-21B-Think pulls ahead
No clear win on a test scored out of 100.
Every test, side by side
All 11 tests both models report. The winning score is in its model's colour; marks a score checked independently.
ReasoningClaude Fable 5
- Humanity's Last ExamClaude Fable 5 by 49.655.55.9+49.6
- GPQA DiamondClaude Fable 5 by 32.592.660.1+32.5
- CritPtClaude Fable 5 by 28.328.60.3+28.3
FactsClaude Fable 5
- AA-Omniscience · AccuracyClaude Fable 5 by 53.165.312.3+53.1
- AA-Omniscience · Non-hallucinationClaude Fable 5 by 21.836.414.6+21.8
Following instructionsClaude Fable 5
- IFBenchClaude Fable 5 by 8.963.554.6+8.9
Other results3 tests, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- AA-OmniscienceClaude Fable 5 by 105.843.3-62.5+105.8
- AA IntelligenceClaude Fable 5 by 40.649.69+40.6
- τ²-Bench Telecom (AA run)Claude Fable 5 by 17.598.581+17.5
Questions people ask
Which is better, Claude Fable 5 or Tri-21B-Think?
Claude Fable 5 wins all five areas where both have results: coding, reasoning, facts, long documents and following instructions. Tri-21B-Think wins none.
Which is better for coding?
Claude Fable 5. It wins the one coding test both models report.
How do you compare the two?
We use the 11 benchmark tests both models have published scores on. The verdict counts the 8 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 3 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.