Noometry

Model comparison

Claude Opus 5 vs Reka Flash 3

Claude Opus 5 has enough public results to be ranked (#4); Reka Flash 3 does not yet, so treat this comparison as directional.

Last verified . 2 shared benchmarks.

Claude Opus 5 Anthropic

67.8

Rank #4 Confirmed

Reka Flash 3 Reka

36.8

Unranked Sparse

Summary

  • They share 2 benchmarks with published results for both. Claude Opus 5 scores higher in 2 categories and Reka Flash 3 in 0 categories; 2 gaps are clear of the uncertainty.
  • The widest gap is in writing & preference, where Claude Opus 5 leads 79.2 to 43.7.
  • The biggest single-benchmark swing is BALROG: 63.4% for Claude Opus 5 and 29.2% for Reka Flash 3.
  • Reka Flash 3 is cheaper at $0.10 / $0.20 per million input/output tokens, against $5 / $25 for Claude Opus 5.
  • Claude Opus 5 accepts more context: 1M tokens versus 66K.
  • Reka Flash 3 has downloadable open weights; the other is API-only.

Side by side

Claude Opus 5Reka Flash 3
ProviderAnthropicReka
Noometry Index67.836.8
Released2026-07-242025-03-10
WeightsProprietaryOpen
Context window1M66K
Max output128K59K
Input $ / M tokens$5$0.10
Output $ / M tokens$25$0.20
Results tracked572

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Category by category

Coding Not comparable

Claude Opus 5: 67.5 (#5), Reka Flash 3: —

BenchmarkClaude Opus 5Reka Flash 3
DeepSWE73.6%—
FrontierCode53.4%—
CursorBench46.6%—
LMArena WebDev1691—
FrontierSWE52%—
SciCode56.4%—
WeirdML91.8%—
LMArena Coding1534—
ALE-Bench2,165—

Agentic & Tool Use Claude Opus 5 leads

Claude Opus 5: 55.6 (#1), Reka Flash 3: 30.4

BenchmarkClaude Opus 5Reka Flash 3
BALROG63.4%29.2%
APEX-Agents65.8%—
OSWorld 2.031.4%—
τ²-bench Banking48.7%—
PostTrainBench35%—
GBAEval79.6%—
GDP.pdf24%—
Vending-Bench 211,182—

Reasoning Not comparable

Claude Opus 5: 77.2 (#4), Reka Flash 3: —

BenchmarkClaude Opus 5Reka Flash 3
ARC-AGI-290.4%—
SimpleBench80.6%—
NYT Connections (extended)94.3%—
ARC-AGI-197.5%—
CritPt29.1%—
Chess Puzzles42%—
EBR-Bench45.7%—
LMArena Hard Prompts1526—
Mystery Game Puzzles59%—
DTBench97.9%—
LMCA64.5%—
Bench to the Future 30.12—
Epoch Capabilities Index162.78—

Math Not comparable

Claude Opus 5: 86.2 (#8), Reka Flash 3: —

BenchmarkClaude Opus 5Reka Flash 3
FrontierMath (Tiers 1-3)85.6%—
FrontierMath Tier 473.2%—
OTIS Mock AIME 2024-202598.9%—
ProofBench99%—
LMArena Math1531—

Knowledge Not comparable

Claude Opus 5: 66.8 (#9), Reka Flash 3: —

BenchmarkClaude Opus 5Reka Flash 3
GPQA Diamond93.9%—
SimpleQA Verified59.9%—
LMArena Expert1557—

Multimodal Not comparable

Claude Opus 5: 50.8 (#8), Reka Flash 3: —

BenchmarkClaude Opus 5Reka Flash 3
LMArena Vision1319—
Blueprint-Bench 230.4%—
Furniture Assembly60.8%—
LMArena Document1516—

Multilingual Not comparable

Claude Opus 5: 58.8 (#4), Reka Flash 3: —

BenchmarkClaude Opus 5Reka Flash 3
LMArena Non-English1501—
LMArena Chinese1574—
LMArena French1519—
LMArena German1524—
LMArena Japanese1516—
LMArena Korean1521—
LMArena Russian1507—
LMArena Spanish1519—

Instruction Following Not comparable

Claude Opus 5: 79.2 (#7), Reka Flash 3: —

BenchmarkClaude Opus 5Reka Flash 3
LMArena Instruction Following1517—

Long Context Not comparable

Claude Opus 5: 46.5 (#21), Reka Flash 3: —

BenchmarkClaude Opus 5Reka Flash 3
LMArena Longer Query1515—

Writing & Preference Claude Opus 5 leads

Claude Opus 5: 79.2 (#1), Reka Flash 3: 43.7

BenchmarkClaude Opus 5Reka Flash 3
EQ-Bench Creative Writing21331228
LMArena Text1507—
LMArena Creative Writing1491—
EQ-Bench 41385—
LMArena Multi-Turn1499—

Frequently asked questions

Is Claude Opus 5 better than Reka Flash 3?

Claude Opus 5 has enough public results to be ranked (#4); Reka Flash 3 does not yet, so treat this comparison as directional.

Which is cheaper, Claude Opus 5 or Reka Flash 3?

Reka Flash 3 is cheaper. It lists at $0.10 per million input tokens and $0.20 per million output tokens; Claude Opus 5 lists at $5 and $25.

Which has the bigger context window?

Claude Opus 5 does, with 1M tokens against 66K.

How many benchmarks do Claude Opus 5 and Reka Flash 3 share?

2 benchmarks have published results for both models. Claude Opus 5 has 57 scored results on Noometry and Reka Flash 3 has 2.

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