Claude Opus 4.5 vs Reka Flash 3
Wins 5 of 5 areas
Coding · Reasoning · Facts · Long documents · Following instructions
Wins 0 of 5 areas
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Claude Opus 4.5 is the stronger all-rounder.Reka Flash 3 is cheaper.
Scores updated · 14 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 Opus 4.53 of 3 tests
- CodingWriting and fixing software20Claude Opus 4.52 of 2 tests
- FactsGetting facts right instead of making them up20Claude Opus 4.52 of 2 tests
- Long documentsFinding answers in very long texts10Claude Opus 4.51 of 1 test
- Following instructionsDoing exactly what it is asked10Claude Opus 4.51 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.
Reka Flash 3 costs 97% 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 Opus 4.5 pulls ahead
- Graduate-level biology, physics and chemistry questionsGPQA Diamond+33.7points ahead
- Answers hard knowledge questions correctlyAA-Omniscience · Accuracy+32.9points ahead
- Avoids making up answers it doesn't knowAA-Omniscience · Non-hallucination+30.3points ahead
Where Reka Flash 3 pulls ahead
No clear win on a test scored out of 100.
Every test, side by side
All 14 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Opus 4.5
- Terminal-Bench HardClaude Opus 4.5 by 47470+47
- SciCodeClaude Opus 4.5 by 22.849.526.7+22.8
ReasoningClaude Opus 4.5
- GPQA DiamondClaude Opus 4.5 by 33.786.652.9+33.7
- Humanity's Last ExamClaude Opus 4.5 by 25.730.14.4+25.7
- CritPtClaude Opus 4.5 by 4.64.60+4.6
FactsClaude Opus 4.5
- AA-Omniscience · AccuracyClaude Opus 4.5 by 32.946.613.7+32.9
- AA-Omniscience · Non-hallucinationClaude Opus 4.5 by 30.3398.7+30.3
Following instructionsClaude Opus 4.5
- IFBenchClaude Opus 4.5 by 27.65830.4+27.6
Other results5 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.
- τ²-Bench Telecom (AA run)Claude Opus 4.5 by 89.589.50+89.5
- AA-OmniscienceClaude Opus 4.5 by 79.114-65.1+79.1
- AA Agentic IndexClaude Opus 4.5 by 59.659.60+59.6
- Artificial Analysis Coding IndexClaude Opus 4.5 by 38.947.88.9+38.9
- AA IntelligenceClaude Opus 4.5 by 23.529.15.6+23.5
Questions people ask
Which is better, Claude Opus 4.5 or Reka Flash 3?
Claude Opus 4.5 wins all five areas where both have results: coding, reasoning, facts, long documents and following instructions. Reka Flash 3 wins none, but costs 97% less.
Which is better for coding?
Claude Opus 4.5. It wins 2 of the 2 coding tests both models report; Reka Flash 3 wins none.
Which is cheaper?
Claude Opus 4.5 costs $5.00 per million input tokens and $25.00 per million output tokens; Reka Flash 3 costs $0.20 and $0.80. That makes Reka Flash 3 about 97% cheaper for the same work.
How do you compare the two?
We use the 14 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 5 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.