JT-4.1 Flash 236B A21B vs Claude Opus 5
Wins 0 of 6 areas
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Wins 5 of 6 areas
Coding · Agents · Reasoning · Images and charts · Long documents
Claude Opus 5 is the stronger all-rounder.
Scores updated · 16 tests both models report · How we compare
Where each one wins
Tests won in each of the six 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.
- AgentsCarrying out multi-step tasks on its own03Claude Opus 53 of 3 tests
- ReasoningHard problems that need careful thinking03Claude Opus 53 of 3 tests
- CodingWriting and fixing software02Claude Opus 52 of 2 tests
- Images and chartsUnderstanding pictures, charts and video01Claude Opus 51 of 1 test
- Long documentsFinding answers in very long texts01Claude Opus 51 of 1 test
- FactsGetting facts right instead of making them up11Even1 each
Images and charts and long documents 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 Opus 5 pulls ahead
- Complex command-line tasks across many fieldsTerminal-Bench 4.0+46points ahead
- Command-line tasks in a real terminalTerminal-Bench 2.1+29.5points ahead
- Harder college exam questions with imagesMMMU-Pro+20.6points ahead
Where JT-4.1 Flash 236B A21B pulls ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+3.8points ahead
Every test, side by side
All 16 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Opus 5
- Terminal-Bench 2.1Claude Opus 5 by 29.559.689.1+29.5
- SciCodeClaude Opus 5 by 4.45256.4+4.4
AgentsClaude Opus 5
- Terminal-Bench 4.0Claude Opus 5 by 46349+46
- GDPValClaude Opus 5 by 19.841.461.2+19.8
- τ-Bench V3 · BankingClaude Opus 5 by 14.12842.1+14.1
ReasoningClaude Opus 5
- CritPtClaude Opus 5 by 15.11429.1+15.1
- Humanity's Last ExamClaude Opus 5 by 11.343.654.9+11.3
- GPQA DiamondClaude Opus 5 by 8.784.593.2+8.7
FactsEven
- AA-Omniscience · AccuracyClaude Opus 5 by 11.549.460.9+11.5
- AA-Omniscience · Non-hallucinationJT-4.1 Flash 236B A21B by 3.84339.2+3.8
Images and chartsClaude Opus 5
- MMMU-ProClaude Opus 5 by 20.664.184.7+20.6
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.
- Artificial Analysis Coding IndexClaude Opus 5 by 25.652.478+25.6
- AA Agentic IndexClaude Opus 5 by 21.334.956.2+21.3
- AA IntelligenceClaude Opus 5 by 16.933.950.8+16.9
- AA-OmniscienceClaude Opus 5 by 16.520.637.1+16.5
Questions people ask
Which is better, JT-4.1 Flash 236B A21B or Claude Opus 5?
Claude Opus 5 wins five of the six areas where both have results: coding, agents, reasoning, images and charts and long documents. JT-4.1 Flash 236B A21B wins none. They are level on facts.
Which is better for coding?
Claude Opus 5. It wins 2 of the 2 coding tests both models report; JT-4.1 Flash 236B A21B wins none.
How do you compare the two?
We use the 16 benchmark tests both models have published scores on. The verdict counts the 12 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.