Model comparison

GPT-5-Codex vs Sonar

GPT-5-Codex and Sonar score almost the same on the Noometry Index (37.9 vs 38.5), so choose on price, context window or the category you care about most.

Last verified . 0 shared benchmarks.

GPT-5-Codex OpenAI

37.9

Rank #192 Reported

Sonar Perplexity

38.5

Rank #187 Confirmed

Summary

  • The widest gap is in reasoning, where GPT-5-Codex leads 30.9 to 21.1.
  • Sonar is cheaper at $1 / $1 per million input/output tokens, against $1.25 / $10 for GPT-5-Codex.
  • GPT-5-Codex accepts more context: 400K tokens versus 128K.

Side by side

GPT-5-Codex and Sonar specifications
GPT-5-CodexSonar
ProviderOpenAIPerplexity
Noometry Index37.938.5
Released2025-09-152024-01-01
WeightsProprietaryProprietary
Context window400K128K
Max output128K4K
Input $ / M tokens$1.25$1
Output $ / M tokens$10$1
Results tracked37

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Category by category

Coding GPT-5-Codex leads

GPT-5-Codex: 42.4 (#103), Sonar: 35.7 (#221)

Coding benchmarks
BenchmarkGPT-5-CodexSonar
WeirdML54.5%—
LiveBench Coding—35.1%

Agentic & Tool Use Not comparable

GPT-5-Codex: 31.0 (#72), Sonar: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5-CodexSonar
Terminal-Bench44.3%—

Reasoning GPT-5-Codex leads

GPT-5-Codex: 30.9 (#83), Sonar: 21.1 (#227)

Reasoning benchmarks
BenchmarkGPT-5-CodexSonar
Kagi LLM Benchmark70.3%—
LiveBench Reasoning—46.3%
LiveBench Data Analysis—37.9%
LiveBench—46.9%

Math Not comparable

GPT-5-Codex: —, Sonar: 33.7 (#200)

Math benchmarks
BenchmarkGPT-5-CodexSonar
LiveBench Math—41.6%

Instruction Following Not comparable

GPT-5-Codex: —, Sonar: 71.4 (#150)

Instruction Following benchmarks
BenchmarkGPT-5-CodexSonar
LiveBench Instruction Following—76.2%

Writing & Preference Not comparable

GPT-5-Codex: —, Sonar: 52.6 (#167)

Writing & Preference benchmarks
BenchmarkGPT-5-CodexSonar
LiveBench Language—44.1%

Frequently asked questions

Is GPT-5-Codex better than Sonar?

GPT-5-Codex and Sonar score almost the same on the Noometry Index (37.9 vs 38.5), so choose on price, context window or the category you care about most.

Which is cheaper, GPT-5-Codex or Sonar?

Sonar is cheaper. It lists at $1 per million input tokens and $1 per million output tokens; GPT-5-Codex lists at $1.25 and $10.

Is GPT-5-Codex or Sonar better for coding?

GPT-5-Codex scores higher on coding benchmarks: 42.4 versus 35.7 in the Noometry coding category.

Which has the bigger context window?

GPT-5-Codex does, with 400K tokens against 128K.

How many benchmarks do GPT-5-Codex and Sonar share?

0 benchmarks have published results for both models. GPT-5-Codex has 3 scored results on Noometry and Sonar has 7.

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