Apertus 8B Instruct vs Claude Fable 5
Wins 0 of 5 areas
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Wins 5 of 5 areas
Coding · Reasoning · Facts · Long documents · Following instructions
Claude Fable 5 is the stronger all-rounder.Apertus 8B Instruct is cheaper.
Scores updated · 13 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 thinking03Claude Fable 53 of 3 tests
- CodingWriting and fixing software02Claude Fable 52 of 2 tests
- FactsGetting facts right instead of making them up02Claude Fable 52 of 2 tests
- Long documentsFinding answers in very long texts01Claude Fable 51 of 1 test
- Following instructionsDoing exactly what it is asked01Claude 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.
Apertus 8B Instruct costs 100% less for the same work.
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
- Graduate-level biology, physics and chemistry questionsGPQA Diamond+67points ahead
- Code for real scientific research problemsSciCode+56.9points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+55.7points ahead
Where Apertus 8B Instruct pulls ahead
No clear win on a test scored out of 100.
Every test, side by side
All 13 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 62.9062.9+62.9
- SciCodeClaude Fable 5 by 56.94.161+56.9
ReasoningClaude Fable 5
- GPQA DiamondClaude Fable 5 by 6725.692.6+67
- Humanity's Last ExamClaude Fable 5 by 50.5555.5+50.5
- CritPtClaude Fable 5 by 28.6028.6+28.6
FactsClaude Fable 5
- AA-Omniscience · AccuracyClaude Fable 5 by 55.79.765.3+55.7
- AA-Omniscience · Non-hallucinationClaude Fable 5 by 32.53.936.4+32.5
Following instructionsClaude Fable 5
- IFBenchClaude Fable 5 by 41.122.463.5+41.1
Other results4 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 120.5-77.243.3+120.5
- τ²-Bench Telecom (AA run)Claude Fable 5 by 87.111.498.5+87.1
- AA Agentic IndexClaude Fable 5 by 47.23.851+47.2
- AA IntelligenceClaude Fable 5 by 44.84.849.6+44.8
Questions people ask
Which is better, Apertus 8B Instruct or Claude Fable 5?
Claude Fable 5 wins all five areas where both have results: coding, reasoning, facts, long documents and following instructions. Apertus 8B Instruct wins none, but costs 100% less.
Which is better for coding?
Claude Fable 5. It wins 2 of the 2 coding tests both models report; Apertus 8B Instruct wins none.
Which is cheaper?
Apertus 8B Instruct costs $0.10 per million input tokens and $0.20 per million output tokens; Claude Fable 5 costs $10.00 and $50.00. That makes Apertus 8B Instruct about 100% cheaper for the same work.
How do you compare the two?
We use the 13 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 4 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.