Noometry

Model comparison

Claude Opus 5.5 vs Solar Pro4

Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 41.5 on the Noometry Index. Solar Pro4 costs 15× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Last verified . 12 shared benchmarks.

Claude Opus 5.5 Anthropic

68.5

Rank #3 Confirmed

Solar Pro4 Upstage

41.5

Rank #123 Confirmed

Summary

  • They share 12 benchmarks with published results for both. Claude Opus 5.5 scores higher in 8 categories and Solar Pro4 in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 5.5 leads 92.4 to 36.1.
  • Solar Pro4 is cheaper at $0.30 / $1.20 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
  • Claude Opus 5.5 accepts more context: 1M tokens versus 524K.

Side by side

Claude Opus 5.5Solar Pro4
ProviderAnthropicUpstage
Noometry Index68.541.5
Released2026-09-222026-08-06
WeightsProprietaryProprietary
Context window1M524K
Max output128K131K
Input $ / M tokens$4$0.30
Output $ / M tokens$20$1.20
Results tracked3518

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Category by category

Coding Claude Opus 5.5 leads

Claude Opus 5.5: 71.4 (#1), Solar Pro4: 39.9 (#135)

BenchmarkClaude Opus 5.5Solar Pro4
LMArena WebDev18201371
LMArena Coding15451439
FrontierCode54.4%—
CursorBench57.8%—
FrontierSWE62.3%—
SciCode66.9%—
MirrorCode77.4%—

Agentic & Tool Use Not comparable

Claude Opus 5.5: 45.3 (#13), Solar Pro4: —

BenchmarkClaude Opus 5.5Solar Pro4
APEX-Agents73.5%—
GDP.pdf30.6%—

Reasoning Claude Opus 5.5 leads

Claude Opus 5.5: 79.5 (#2), Solar Pro4: 27.3 (#107)

BenchmarkClaude Opus 5.5Solar Pro4
LMArena Hard Prompts15451398
ARC-AGI-292.5%—
NYT Connections (extended)88.5%—
ARC-AGI-197.5%—
CritPt31.7%—
EBR-Bench71.4%—
Mystery Game Puzzles71%—
DTBench98.9%—
LMCA68.2%—

Math Claude Opus 5.5 leads

Claude Opus 5.5: 92.4 (#2), Solar Pro4: 36.1 (#129)

BenchmarkClaude Opus 5.5Solar Pro4
FrontierMath (Tiers 1-3)91.2%—
FrontierMath Tier 495%—
OTIS Mock AIME 2024-2025100%—
ProofBench100%—
LMArena Math—1418

Knowledge Claude Opus 5.5 leads

Claude Opus 5.5: 66.6 (#9), Solar Pro4: 39.0 (#128)

BenchmarkClaude Opus 5.5Solar Pro4
LMArena Expert15641421
GPQA Diamond90.6%—
SimpleQA Verified72.2%—

Multimodal Not comparable

Claude Opus 5.5: 56.5 (#2), Solar Pro4: —

BenchmarkClaude Opus 5.5Solar Pro4
Furniture Assembly83.3%—

Multilingual Claude Opus 5.5 leads

Claude Opus 5.5: 59.8 (#1), Solar Pro4: 49.0 (#134)

BenchmarkClaude Opus 5.5Solar Pro4
LMArena Non-English15131362
LMArena Chinese15721417
LMArena Russian15321360
LMArena French—1403
LMArena German—1351
LMArena Japanese—1300
LMArena Korean—1383
LMArena Spanish—1408

Instruction Following Claude Opus 5.5 leads

Claude Opus 5.5: 80.1 (#2), Solar Pro4: 72.8 (#128)

BenchmarkClaude Opus 5.5Solar Pro4
LMArena Instruction Following15351376

Long Context Claude Opus 5.5 leads

Claude Opus 5.5: 47.3 (#18), Solar Pro4: 42.0 (#125)

BenchmarkClaude Opus 5.5Solar Pro4
LMArena Longer Query15401379

Writing & Preference Claude Opus 5.5 leads

Claude Opus 5.5: 78.7 (#3), Solar Pro4: 56.7 (#133)

BenchmarkClaude Opus 5.5Solar Pro4
LMArena Text15181386
LMArena Creative Writing15381313
LMArena Multi-Turn15201391
EQ-Bench Creative Writing2050—

Frequently asked questions

Is Claude Opus 5.5 better than Solar Pro4?

Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 41.5 on the Noometry Index. Solar Pro4 costs 15× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 5.5 or Solar Pro4?

Solar Pro4 is cheaper. It lists at $0.30 per million input tokens and $1.20 per million output tokens; Claude Opus 5.5 lists at $4 and $20.

Is Claude Opus 5.5 or Solar Pro4 better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.4 versus 39.9 in the Noometry coding category.

Which has the bigger context window?

Claude Opus 5.5 does, with 1M tokens against 524K.

How many benchmarks do Claude Opus 5.5 and Solar Pro4 share?

12 benchmarks have published results for both models. Claude Opus 5.5 has 35 scored results on Noometry and Solar Pro4 has 18.

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