Model comparison

Claude Opus 4.8 vs Claude Sonnet 5

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 54.6 on the Noometry Index. Claude Sonnet 5 costs 2.5× less per token, which makes it the better buy when Claude Opus 4.8's lead doesn't matter for your workload.

Last verified . 50 shared benchmarks.

Claude Opus 4.8 Anthropic

60.7

Rank #13 Confirmed

Claude Sonnet 5 Anthropic

54.6

Rank #29 Confirmed

Summary

  • They share 50 benchmarks with published results for both. Claude Opus 4.8 scores higher in 10 categories and Claude Sonnet 5 in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Opus 4.8 leads 64.7 to 49.1.
  • The biggest single-benchmark swing is Surface Evolver Bench: 87.5% for Claude Opus 4.8 and 60% for Claude Sonnet 5.
  • Claude Sonnet 5 is cheaper at $2 / $10 per million input/output tokens, against $5 / $25 for Claude Opus 4.8.

Side by side

Claude Opus 4.8 and Claude Sonnet 5 specifications
Claude Opus 4.8Claude Sonnet 5
ProviderAnthropicAnthropic
Noometry Index60.754.6
Released2026-05-282026-06-29
WeightsProprietaryProprietary
Context window1M1M
Max output128K128K
Input $ / M tokens$5$2
Output $ / M tokens$25$10
Results tracked6551

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Category by category

Coding Claude Opus 4.8 leads

Claude Opus 4.8: 59.9 (#12), Claude Sonnet 5: 55.5 (#26)

Coding benchmarks
BenchmarkClaude Opus 4.8Claude Sonnet 5
DeepSWE59%53.8%
FrontierCode46.5%42.7%
LMArena WebDev15561541
SciCode53.5%54.3%
GSO47.1%37.3%
WeirdML82.9%68.8%
LMArena Coding14901483
ALE-Bench1,5641,463
CursorBench—34.1%

Agentic & Tool Use Claude Opus 4.8 leads

Claude Opus 4.8: 47.6 (#11), Claude Sonnet 5: 42.8 (#18)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4.8Claude Sonnet 5
APEX-Agents48.9%54.5%
GBAEval70.9%65.3%
LMArena Search12041194
Vending-Bench 25,7876,378
OSWorld 2.020.6%—
Remote Labor Index8.3%—
τ²-bench Banking39.7%—
DeepResearch Bench50.2%—
PostTrainBench33.8%—
GDP.pdf24%—

Reasoning Claude Opus 4.8 leads

Claude Opus 4.8: 64.7 (#16), Claude Sonnet 5: 49.1 (#39)

Reasoning benchmarks
BenchmarkClaude Opus 4.8Claude Sonnet 5
SimpleBench64.8%60.6%
NYT Connections (extended)91.1%75.1%
CritPt20.9%16.9%
Chess Puzzles34%35%
LMArena Hard Prompts14821461
Mystery Game Puzzles36%35%
DTBench94.9%92.5%
LMCA57.5%50%
Surface Evolver Bench87.5%60%
Bench to the Future 30.140.14
Epoch Capabilities Index158.21156.21
ForecastBench59.961.1
ARC-AGI-272.1%—
Kagi LLM Benchmark88.8%—
ARC-AGI-192.5%—
EnigmaEval23.5%—
EBR-Bench28.6%—

Math Claude Opus 4.8 leads

Claude Opus 4.8: 78.4 (#13), Claude Sonnet 5: 66.2 (#27)

Math benchmarks
BenchmarkClaude Opus 4.8Claude Sonnet 5
FrontierMath (Tiers 1-3)80%65.6%
FrontierMath Tier 456.1%29.3%
OTIS Mock AIME 2024-202598.3%94.7%
ProofBench69%77%
LMArena Math14871467
MathArena Final-Answer Competitions91.8%—
FrontierMath (Feb 2025 set)47.2%—
FrontierMath Tier 4 (v1)31.3%—

Knowledge Claude Opus 4.8 leads

Claude Opus 4.8: 61.3 (#29), Claude Sonnet 5: 55.6 (#47)

Knowledge benchmarks
BenchmarkClaude Opus 4.8Claude Sonnet 5
GPQA Diamond91%90.5%
SimpleQA Verified53%33.7%
LMArena Expert15021490

Multimodal Too close to call

Claude Opus 4.8: 42.9 (#26), Claude Sonnet 5: 42.4 (#31)

Multimodal benchmarks
BenchmarkClaude Opus 4.8Claude Sonnet 5
LMArena Vision12941274
Blueprint-Bench 214.5%24.9%
LMArena Document14751466
Furniture Assembly42.5%—

Multilingual Claude Opus 4.8 leads

Claude Opus 4.8: 55.2 (#33), Claude Sonnet 5: 53.8 (#55)

Multilingual benchmarks
BenchmarkClaude Opus 4.8Claude Sonnet 5
LMArena Non-English14501431
LMArena Chinese15071477
LMArena French14811460
LMArena German14721440
LMArena Japanese14401422
LMArena Korean14321411
LMArena Russian14741451
LMArena Spanish14661437

Instruction Following Claude Opus 4.8 leads

Claude Opus 4.8: 77.4 (#24), Claude Sonnet 5: 76.3 (#41)

Instruction Following benchmarks
BenchmarkClaude Opus 4.8Claude Sonnet 5
LMArena Instruction Following14761452

Long Context Too close to call

Claude Opus 4.8: 45.4 (#35), Claude Sonnet 5: 44.8 (#55)

Long Context benchmarks
BenchmarkClaude Opus 4.8Claude Sonnet 5
LMArena Longer Query14831463

Writing & Preference Claude Opus 4.8 leads

Claude Opus 4.8: 72.0 (#16), Claude Sonnet 5: 69.2 (#25)

Writing & Preference benchmarks
BenchmarkClaude Opus 4.8Claude Sonnet 5
LMArena Text14611442
LMArena Creative Writing14541416
EQ-Bench Creative Writing18401794
EQ-Bench 412811236
LMArena Multi-Turn14761454

Frequently asked questions

Is Claude Opus 4.8 better than Claude Sonnet 5?

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 54.6 on the Noometry Index. Claude Sonnet 5 costs 2.5× less per token, which makes it the better buy when Claude Opus 4.8's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 4.8 or Claude Sonnet 5?

Claude Sonnet 5 is cheaper. It lists at $2 per million input tokens and $10 per million output tokens; Claude Opus 4.8 lists at $5 and $25.

Is Claude Opus 4.8 or Claude Sonnet 5 better for coding?

Claude Opus 4.8 scores higher on coding benchmarks: 59.9 versus 55.5 in the Noometry coding category.

Which has the bigger context window?

Both accept 1M tokens.

How many benchmarks do Claude Opus 4.8 and Claude Sonnet 5 share?

50 benchmarks have published results for both models. Claude Opus 4.8 has 65 scored results on Noometry and Claude Sonnet 5 has 51.

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