Noometry

Model comparison

Claude Opus 4.5 vs Claude Opus 4.8

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 50.5 on the Noometry Index.

Last verified . 50 shared benchmarks.

Claude Opus 4.5 Anthropic

50.5

Rank #47 Confirmed

Claude Opus 4.8 Anthropic

60.7

Rank #13 Confirmed

Summary

  • They share 50 benchmarks with published results for both. Claude Opus 4.5 scores higher in 2 categories and Claude Opus 4.8 in 8 categories; 7 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 4.8 leads 78.4 to 38.6.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 4.9% for Claude Opus 4.5 and 56.1% for Claude Opus 4.8.
  • Both cost about the same: $5 input and $25 output per million tokens.
  • Claude Opus 4.8 accepts more context: 1M tokens versus 200K.

Side by side

Claude Opus 4.5Claude Opus 4.8
ProviderAnthropicAnthropic
Noometry Index50.560.7
Released2025-11-012026-05-28
WeightsProprietaryProprietary
Context window200K1M
Max output64K128K
Input $ / M tokens$5$5
Output $ / M tokens$25$25
Results tracked6965

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Category by category

Coding Claude Opus 4.8 leads

Claude Opus 4.5: 54.8 (#27), Claude Opus 4.8: 59.9 (#12)

BenchmarkClaude Opus 4.5Claude Opus 4.8
LMArena WebDev14941556
GSO26.5%47.1%
WeirdML63.7%82.9%
LMArena Coding15041490
ALE-Bench1,0251,564
SWE-bench Verified76.7%—
DeepSWE—59%
FrontierCode—46.5%
SWE-bench Verified (bash only)76.8%—
SWE-bench Multilingual70.7%—
SciCode—53.5%
AlgoTune1.77—

Agentic & Tool Use Too close to call

Claude Opus 4.5: 47.3 (#12), Claude Opus 4.8: 47.6 (#11)

BenchmarkClaude Opus 4.5Claude Opus 4.8
Remote Labor Index3.8%8.3%
τ²-bench Banking24.7%39.7%
DeepResearch Bench54.8%50.2%
LMArena Search11801204
Vending-Bench 24,9675,787
Terminal-Bench63.1%—
APEX-Agents—48.9%
Berkeley Function Calling Leaderboard77.5%—
OSWorld 2.0—20.6%
GDPval45.5%—
τ²-bench Airline84%—
τ²-bench Retail79.6%—
τ²-bench Telecom92.3%—
Cybench82%—
OSWorld66.3%—
PostTrainBench—33.8%
BALROG43.5%—
GBAEval—70.9%
GDP.pdf—24%
METR Time Horizons75%—

Reasoning Claude Opus 4.8 leads

Claude Opus 4.5: 42.6 (#51), Claude Opus 4.8: 64.7 (#16)

BenchmarkClaude Opus 4.5Claude Opus 4.8
ARC-AGI-237.6%72.1%
SimpleBench62%64.8%
Kagi LLM Benchmark80.2%88.8%
NYT Connections (extended)52.5%91.1%
ARC-AGI-180%92.5%
Chess Puzzles12%34%
EnigmaEval11.9%23.5%
EBR-Bench14.3%28.6%
LMArena Hard Prompts14761482
Mystery Game Puzzles22%36%
DTBench89.9%94.9%
LMCA44.5%57.5%
Epoch Capabilities Index150.09158.21
ForecastBench60.759.9
CritPt—20.9%
Surface Evolver Bench—87.5%
Bench to the Future 3—0.14

Math Claude Opus 4.8 leads

Claude Opus 4.5: 38.6 (#132), Claude Opus 4.8: 78.4 (#13)

BenchmarkClaude Opus 4.5Claude Opus 4.8
FrontierMath (Tiers 1-3)34.4%80%
FrontierMath Tier 44.9%56.1%
OTIS Mock AIME 2024-202586.1%98.3%
ProofBench36%69%
LMArena Math14631487
FrontierMath (Feb 2025 set)20.7%47.2%
FrontierMath Tier 4 (v1)4.2%31.3%
MathArena Final-Answer Competitions—91.8%

Knowledge Claude Opus 4.8 leads

Claude Opus 4.5: 56.5 (#44), Claude Opus 4.8: 61.3 (#29)

BenchmarkClaude Opus 4.5Claude Opus 4.8
GPQA Diamond86%91%
SimpleQA Verified45.7%53%
LMArena Expert14871502
Humanity's Last Exam25.2%—
Vectara Hallucination Rate10.9%—

Multimodal Claude Opus 4.8 leads

Claude Opus 4.5: 31.4 (#107), Claude Opus 4.8: 42.9 (#26)

BenchmarkClaude Opus 4.5Claude Opus 4.8
Furniture Assembly28.3%42.5%
LMArena Document14621475
LMArena Vision—1294
GeoBench75%—
VPCT40%—
Blueprint-Bench 2—14.5%

Multilingual Too close to call

Claude Opus 4.5: 54.3 (#47), Claude Opus 4.8: 55.2 (#33)

BenchmarkClaude Opus 4.5Claude Opus 4.8
LMArena Non-English14381450
LMArena Chinese14701507
LMArena French14711481
LMArena German14491472
LMArena Japanese14161440
LMArena Korean14241432
LMArena Russian14471474
LMArena Spanish14581466

Instruction Following Too close to call

Claude Opus 4.5: 77.5 (#19), Claude Opus 4.8: 77.4 (#24)

BenchmarkClaude Opus 4.5Claude Opus 4.8
LMArena Instruction Following14781476

Long Context Claude Opus 4.5 leads

Claude Opus 4.5: 46.5 (#22), Claude Opus 4.8: 45.4 (#35)

BenchmarkClaude Opus 4.5Claude Opus 4.8
LMArena Longer Query14801483
CL-bench21.1%—

Writing & Preference Claude Opus 4.8 leads

Claude Opus 4.5: 68.1 (#28), Claude Opus 4.8: 72.0 (#16)

BenchmarkClaude Opus 4.5Claude Opus 4.8
LMArena Text14511461
LMArena Creative Writing14451454
EQ-Bench Creative Writing16871840
LMArena Multi-Turn14661476
EQ-Bench 4—1281

Frequently asked questions

Is Claude Opus 4.5 better than Claude Opus 4.8?

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 50.5 on the Noometry Index.

Which is cheaper, Claude Opus 4.5 or Claude Opus 4.8?

Claude Opus 4.8 is cheaper. It lists at $5 per million input tokens and $25 per million output tokens; Claude Opus 4.5 lists at $5 and $25.

Is Claude Opus 4.5 or Claude Opus 4.8 better for coding?

Claude Opus 4.8 scores higher on coding benchmarks: 59.9 versus 54.8 in the Noometry coding category.

Which has the bigger context window?

Claude Opus 4.8 does, with 1M tokens against 200K.

How many benchmarks do Claude Opus 4.5 and Claude Opus 4.8 share?

50 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and Claude Opus 4.8 has 65.

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