Claude Fable 5 vs K2-V2 (high)
Wins 5 of 5 areas
Coding · Reasoning · Facts · Long documents · Following instructions
Wins 0 of 5 areas
—
Claude Fable 5 is the stronger all-rounder.
Scores updated · 12 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
- CodingWriting and fixing software20Claude Fable 52 of 2 tests
- FactsGetting facts right instead of making them up20Claude Fable 52 of 2 tests
- Long documentsFinding answers in very long texts10Claude Fable 51 of 1 test
- Following instructionsDoing exactly what it is asked10Claude Fable 51 of 1 test
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
- Hard command-line tasks in a real terminalTerminal-Bench Hard+53.1points ahead
- Reasons across sets of long documentsAA-LCR+47.3points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+46.9points ahead
Where K2-V2 (high) pulls ahead
No clear win on a test scored out of 100.
Every test, side by side
All 12 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Fable 5
- Terminal-Bench HardClaude Fable 5 by 53.162.99.8+53.1
- SciCodeClaude Fable 5 by 32.46128.6+32.4
ReasoningClaude Fable 5
- Humanity's Last ExamClaude Fable 5 by 4555.510.5+45
- CritPtClaude Fable 5 by 28.628.60+28.6
- GPQA DiamondClaude Fable 5 by 24.592.668.1+24.5
FactsClaude Fable 5
- AA-Omniscience · AccuracyClaude Fable 5 by 46.965.318.5+46.9
- AA-Omniscience · Non-hallucinationClaude Fable 5 by 27.436.49+27.4
Following instructionsClaude Fable 5
- IFBenchClaude Fable 5 by 3.463.560.1+3.4
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 98.943.3-55.6+98.9
- τ²-Bench Telecom (AA run)Claude Fable 5 by 70.798.527.8+70.7
- AA IntelligenceClaude Fable 5 by 39.749.69.9+39.7
Questions people ask
Which is better, Claude Fable 5 or K2-V2 (high)?
Claude Fable 5 wins all five areas where both have results: coding, reasoning, facts, long documents and following instructions. K2-V2 (high) wins none.
Which is better for coding?
Claude Fable 5. It wins 2 of the 2 coding tests both models report; K2-V2 (high) wins none.
How do you compare the two?
We use the 12 benchmark tests both models have published scores on. The verdict counts the 9 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.