Noometry

Model comparison

Claude Fable 5.1 vs Solar Pro4

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 42.1 on the Noometry Index. Solar Pro4 costs 38× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.

Last verified . 18 shared benchmarks.

Claude Fable 5.1 Anthropic

69.0

Rank #2 Confirmed

Solar Pro4 Upstage

42.1

Rank #121 Confirmed

Summary

  • They share 18 benchmarks with published results for both. Claude Fable 5.1 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 Fable 5.1 leads 89.6 to 38.8.
  • Solar Pro4 is cheaper at $0.30 / $1.20 per million input/output tokens, against $10 / $50 for Claude Fable 5.1.
  • Claude Fable 5.1 accepts more context: 1M tokens versus 524K.

Side by side

Claude Fable 5.1Solar Pro4
ProviderAnthropicUpstage
Noometry Index69.042.1
Released2026-09-012026-08-06
WeightsProprietaryProprietary
Context window1M524K
Max output128K131K
Input $ / M tokens$10$0.30
Output $ / M tokens$50$1.20
Results tracked5218

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Category by category

Coding Claude Fable 5.1 leads

Claude Fable 5.1: 74.7 (#1), Solar Pro4: 40.1 (#149)

BenchmarkClaude Fable 5.1Solar Pro4
LMArena WebDev17441371
LMArena Coding15281437
FrontierCode50.9%—
CursorBench51.8%—
FrontierSWE56.3%—
SciCode63.1%—
GSO88.2%—
WeirdML92.9%—
MirrorCode73.3%—
ALE-Bench2,143—

Agentic & Tool Use Not comparable

Claude Fable 5.1: 50.7 (#5), Solar Pro4: —

BenchmarkClaude Fable 5.1Solar Pro4
APEX-Agents68.6%—
Remote Labor Index17.9%—
GDP.pdf29.6%—
Vending-Bench 25,422—

Reasoning Claude Fable 5.1 leads

Claude Fable 5.1: 76.7 (#7), Solar Pro4: 28.5 (#104)

BenchmarkClaude Fable 5.1Solar Pro4
LMArena Hard Prompts15261399
ARC-AGI-290%—
NYT Connections (extended)90%—
ARC-AGI-197.5%—
CritPt31.1%—
Chess Puzzles47%—
EBR-Bench57.1%—
Mystery Game Puzzles58%—
DTBench97.6%—
LMCA65.5%—
Epoch Capabilities Index164.7—

Math Claude Fable 5.1 leads

Claude Fable 5.1: 89.6 (#4), Solar Pro4: 38.8 (#128)

BenchmarkClaude Fable 5.1Solar Pro4
LMArena Math15251416
FrontierMath (Tiers 1-3)90.2%—
FrontierMath Tier 487.8%—
OTIS Mock AIME 2024-2025100%—
ProofBench100%—
FrontierMath Erdős0%—

Knowledge Claude Fable 5.1 leads

Claude Fable 5.1: 69.6 (#6), Solar Pro4: 39.8 (#129)

BenchmarkClaude Fable 5.1Solar Pro4
LMArena Expert15351427
Humanity's Last Exam46.5%—
SimpleQA Verified70.8%—

Multimodal Not comparable

Claude Fable 5.1: 53.9 (#4), Solar Pro4: —

BenchmarkClaude Fable 5.1Solar Pro4
LMArena Vision1318—
Blueprint-Bench 241.9%—
Furniture Assembly70%—
LMArena Document1513—

Multilingual Claude Fable 5.1 leads

Claude Fable 5.1: 59.1 (#3), Solar Pro4: 48.7 (#139)

BenchmarkClaude Fable 5.1Solar Pro4
LMArena Non-English15071361
LMArena Chinese15861415
LMArena French15251397
LMArena German15001364
LMArena Japanese15431309
LMArena Korean15341382
LMArena Russian15211360
LMArena Spanish15161401

Instruction Following Claude Fable 5.1 leads

Claude Fable 5.1: 79.2 (#6), Solar Pro4: 72.7 (#132)

BenchmarkClaude Fable 5.1Solar Pro4
LMArena Instruction Following15171377

Long Context Claude Fable 5.1 leads

Claude Fable 5.1: 46.7 (#20), Solar Pro4: 42.1 (#130)

BenchmarkClaude Fable 5.1Solar Pro4
LMArena Longer Query15221381

Writing & Preference Claude Fable 5.1 leads

Claude Fable 5.1: 79.2 (#2), Solar Pro4: 56.5 (#138)

BenchmarkClaude Fable 5.1Solar Pro4
LMArena Text15101386
LMArena Creative Writing15071316
LMArena Multi-Turn14921385
EQ-Bench Creative Writing2162—

Frequently asked questions

Is Claude Fable 5.1 better than Solar Pro4?

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 42.1 on the Noometry Index. Solar Pro4 costs 38× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.

Which is cheaper, Claude Fable 5.1 or Solar Pro4?

Solar Pro4 is cheaper. It lists at $0.30 per million input tokens and $1.20 per million output tokens; Claude Fable 5.1 lists at $10 and $50.

Is Claude Fable 5.1 or Solar Pro4 better for coding?

Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 40.1 in the Noometry coding category.

Which has the bigger context window?

Claude Fable 5.1 does, with 1M tokens against 524K.

How many benchmarks do Claude Fable 5.1 and Solar Pro4 share?

18 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and Solar Pro4 has 18.

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