Claude Opus 4.5 vs Kimi K2 Thinking
Wins 5 of 7 areas
Coding · Reasoning · Facts · Math · Long documents
Wins 0 of 7 areas
—
Claude Opus 4.5 is the stronger all-rounder.Kimi K2 Thinking is cheaper.
Scores updated · 35 tests both models report · How we compare
Where each one wins
Tests won in each of the seven 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.
- CodingWriting and fixing software41Claude Opus 4.54 of 5 tests
- ReasoningHard problems that need careful thinking30Claude Opus 4.53 of 3 tests
- FactsGetting facts right instead of making them up20Claude Opus 4.52 of 2 tests
- Long documentsFinding answers in very long texts20Claude Opus 4.52 of 2 tests
- MathCompetition and research-level math10Claude Opus 4.51 of 1 test
- AgentsCarrying out multi-step tasks on its own11Even1 each
- Following instructionsDoing exactly what it is asked11Even1 each
Math rests on a single test.
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.
Kimi K2 Thinking costs 90% less for the same work.
The biggest differences
The three tests each model wins by the widest margin. Scores are out of 100.
Where Claude Opus 4.5 pulls ahead
- Real work tasks from 44 professionsGDPVal+22.8points ahead
- Questions about very long textsLongBench v2+19.3points ahead
- Fixes real GitHub issues in Python projectsSWE-bench Verified+17.5points ahead
Where Kimi K2 Thinking pulls ahead
- Fixes real GitHub issues in many programming languagesSWE-bench Multilingual+54.1points ahead
- Follows unfamiliar, precisely checkable instructionsIFBench+10.1points ahead
- Finds hard-to-locate facts by browsing the webBrowseComp+4.5points ahead
Every test, side by side
All 35 tests both models report. The winning score is in its model's colour; marks a score checked independently.
CodingClaude Opus 4.5
- SWE-bench MultilingualKimi K2 Thinking by 54.1761.1+54.1
- SWE-bench VerifiedClaude Opus 4.5 by 17.580.963.4+17.5
- Terminal-Bench HardClaude Opus 4.5 by 15.94731.1+15.9
- SciCodeClaude Opus 4.5 by 7.149.542.4+7.1
- LiveCodeBench v6Claude Opus 4.5 by 1.784.883.1+1.7
AgentsEven
- GDPValClaude Opus 4.5 by 22.847.324.5+22.8
- BrowseCompKimi K2 Thinking by 4.53741.5+4.5
ReasoningClaude Opus 4.5
- Humanity's Last ExamClaude Opus 4.5 by 6.330.123.8+6.3
- GPQA DiamondClaude Opus 4.5 by 2.886.683.8+2.8
- CritPtClaude Opus 4.5 by 24.62.6+2
FactsClaude Opus 4.5
- AA-Omniscience · AccuracyClaude Opus 4.5 by 15.746.630.9+15.7
- AA-Omniscience · Non-hallucinationClaude Opus 4.5 by 14.63924.4+14.6
Long documentsClaude Opus 4.5
- LongBench v2Claude Opus 4.5 by 19.364.445.1+19.3
- AA-LCRClaude Opus 4.5 by 5.377.372+5.3
Following instructionsEven
- IFBenchKimi K2 Thinking by 10.15868.1+10.1
- Multi-ChallengeClaude Opus 4.5 by 3.65955.4+3.6
Other results18 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 Opus 4.5 by 35.414-21.4+35.4
- τ²-BenchClaude Opus 4.5 by 23.998.274.3+23.9
- Terminal-Bench 2.0Claude Opus 4.5 by 23.659.335.7+23.6
- Artificial Analysis Coding IndexClaude Opus 4.5 by 1347.834.8+13
- AA Agentic IndexClaude Opus 4.5 by 11.759.647.9+11.7
- swe_bench_bashClaude Opus 4.5 by 1174.463.4+11
- LiveCodeBenchClaude Opus 4.5 by 7.88779.2+7.8
- AA IntelligenceClaude Opus 4.5 by 7.129.122+7.1
- OJ-Bench (cpp)Claude Opus 4.5 by 5.954.648.7+5.9
- MMLU-ProClaude Opus 4.5 by 4.989.584.6+4.9
- frontiermath_tier_4_v1Claude Opus 4.5 by 4.24.20+4.2
- HMMT Nov. 2025Claude Opus 4.5 by 4.193.389.2+4.1
- AIME25 no toolsKimi K2 Thinking by 3.59194.5+3.5
- τ²-Bench Telecom (AA run)Kimi K2 Thinking by 3.589.593+3.5
- AIME 2025Kimi K2 Thinking by 1.792.894.5+1.7
- HLE (with tools)Kimi K2 Thinking by 1.743.244.9+1.7
- MMLU-ReduxClaude Opus 4.5 by 1.295.694.4+1.2
- HMMT Feb. 2025tie92.993.3tie
Questions people ask
Which is better, Claude Opus 4.5 or Kimi K2 Thinking?
Claude Opus 4.5 wins five of the seven areas where both have results: coding, reasoning, facts, math and long documents. Kimi K2 Thinking wins none, but costs 90% less. They are level on agents and following instructions.
Which is better for coding?
Claude Opus 4.5. It wins 4 of the 5 coding tests both models report; Kimi K2 Thinking wins 1.
Which is cheaper?
Claude Opus 4.5 costs $5.00 per million input tokens and $25.00 per million output tokens; Kimi K2 Thinking costs $0.60 and $2.50. That makes Kimi K2 Thinking about 90% cheaper for the same work.
How do you compare the two?
We use the 35 benchmark tests both models have published scores on. The verdict counts the 17 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 18 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.