Model comparison

GPT-5.1 vs Sonar

GPT-5.1 is the stronger model overall, scoring 49.0 to 38.5 on the Noometry Index. Sonar costs 3.4× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Last verified . 7 shared benchmarks.

GPT-5.1 OpenAI

49.0

Rank #53 Confirmed

Sonar Perplexity

38.5

Rank #187 Confirmed

Summary

  • They share 7 benchmarks with published results for both. GPT-5.1 scores higher in 5 categories and Sonar in 0 categories; 5 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.1 leads 39.8 to 21.1.
  • The biggest single-benchmark swing is LiveBench Math: 94.5% for GPT-5.1 and 41.6% for Sonar.
  • Sonar is cheaper at $1 / $1 per million input/output tokens, against $1.25 / $10 for GPT-5.1.
  • GPT-5.1 accepts more context: 400K tokens versus 128K.

Side by side

GPT-5.1 and Sonar specifications
GPT-5.1Sonar
ProviderOpenAIPerplexity
Noometry Index49.038.5
Released2025-11-132024-01-01
WeightsProprietaryProprietary
Context window400K128K
Max output128K4K
Input $ / M tokens$1.25$1
Output $ / M tokens$10$1
Results tracked637

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Category by category

Coding GPT-5.1 leads

GPT-5.1: 46.4 (#66), Sonar: 35.7 (#221)

Coding benchmarks
BenchmarkGPT-5.1Sonar
LiveBench Coding72.5%35.1%
SWE-bench Verified68%—
SWE-bench Verified (bash only)66%—
LMArena WebDev1395—
SciCode43.3%—
GSO13.7%—
WeirdML60.8%—
LMArena Coding1454—
ALE-Bench1,192—

Agentic & Tool Use Not comparable

GPT-5.1: 32.7 (#60), Sonar: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1Sonar
Terminal-Bench47.6%—
DeepResearch Bench42.8%—
LMArena Search1199—
Vending-Bench 21,473—

Reasoning GPT-5.1 leads

GPT-5.1: 39.8 (#58), Sonar: 21.1 (#227)

Reasoning benchmarks
BenchmarkGPT-5.1Sonar
LiveBench Reasoning95.8%46.3%
LiveBench Data Analysis72.1%37.9%
LiveBench78.8%46.9%
ARC-AGI-217.6%—
SimpleBench53.2%—
ARC-AGI-172.8%—
CritPt4.9%—
Chess Puzzles32%—
EnigmaEval11.2%—
LMArena Hard Prompts1457—
Mystery Game Puzzles19%—
DTBench90.1%—
LMCA43.9%—
Epoch Capabilities Index149.64—
ForecastBench58.1—

Math GPT-5.1 leads

GPT-5.1: 52.2 (#51), Sonar: 33.7 (#200)

Math benchmarks
BenchmarkGPT-5.1Sonar
LiveBench Math94.5%41.6%
OTIS Mock AIME 2024-202588.6%—
Omni-MATH46.4%—
LMArena Math1447—
FrontierMath (Feb 2025 set)31%—
FrontierMath Tier 4 (v1)12.5%—

Knowledge Not comparable

GPT-5.1: 50.6 (#71), Sonar: —

Knowledge benchmarks
BenchmarkGPT-5.1Sonar
GPQA Diamond87.6%—
Humanity's Last Exam23.7%—
SimpleQA Verified48%—
MMLU-Pro57.9%—
Vectara Hallucination Rate10.9%—
GPQA (HELM)44.2%—
LMArena Expert1470—

Multimodal Not comparable

GPT-5.1: 44.8 (#19), Sonar: —

Multimodal benchmarks
BenchmarkGPT-5.1Sonar
LMArena Vision1250—
VPCT58.7%—
LMArena Document1403—

Multilingual Not comparable

GPT-5.1: 53.8 (#56), Sonar: —

Multilingual benchmarks
BenchmarkGPT-5.1Sonar
LMArena Non-English1431—
LMArena Chinese1495—
LMArena French1450—
LMArena German1438—
LMArena Japanese1453—
LMArena Korean1401—
LMArena Russian1435—
LMArena Spanish1433—

Instruction Following GPT-5.1 leads

GPT-5.1: 83.9 (#1), Sonar: 71.4 (#150)

Instruction Following benchmarks
BenchmarkGPT-5.1Sonar
LiveBench Instruction Following93.3%76.2%
IFEval93.5%—
LMArena Instruction Following1443—

Long Context Not comparable

GPT-5.1: 47.6 (#14), Sonar: —

Long Context benchmarks
BenchmarkGPT-5.1Sonar
CL-bench23.7%—
CL-bench Life17.3%—
LMArena Longer Query1447—

Writing & Preference GPT-5.1 leads

GPT-5.1: 64.5 (#55), Sonar: 52.6 (#167)

Writing & Preference benchmarks
BenchmarkGPT-5.1Sonar
LiveBench Language80.2%44.1%
LMArena Text1443—
LMArena Creative Writing1427—
WildBench86.3%—
LMArena Multi-Turn1450—

Frequently asked questions

Is GPT-5.1 better than Sonar?

GPT-5.1 is the stronger model overall, scoring 49.0 to 38.5 on the Noometry Index. Sonar costs 3.4× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Which is cheaper, GPT-5.1 or Sonar?

Sonar is cheaper. It lists at $1 per million input tokens and $1 per million output tokens; GPT-5.1 lists at $1.25 and $10.

Is GPT-5.1 or Sonar better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.4 versus 35.7 in the Noometry coding category.

Which has the bigger context window?

GPT-5.1 does, with 400K tokens against 128K.

How many benchmarks do GPT-5.1 and Sonar share?

7 benchmarks have published results for both models. GPT-5.1 has 63 scored results on Noometry and Sonar has 7.

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