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AI Choice Engine

Model comparison

Claude Sonnet 5 vs GPT-6 Sol

Anthropic against OpenAI, compared on context, price, and verified benchmark results.

Catalog record checked September 26, 2026Individual provider fields may changeEvidence confidence: High — see receipts below

Anthropic

Claude Sonnet 5

Balanced

vs

OpenAI

GPT-6 Sol

Balanced

AI model capability comparison
SpecificationClaude Sonnet 5GPT-6 Sol
ProviderAnthropicOpenAI
TierBalancedBalanced
Context window1MWinner: 1.05M
Max output128K128K
Input / 1M tokens$2$2
Output / 1M tokens$10$10
WeightsClosedClosed
ParametersNot disclosedUnverifiedGPT-6 mid-price tier
Reasoning levelsadaptivenone, low, medium, high, xhigh, max
Modalitiestext, imagetext, image
API model idclaude-sonnet-5gpt-6-sol
ReleasedJune 30, 2026September 22, 2026
Artificial Analysis Intelligence Index [max] (2026-09-26)38.2Winner: 47.5
Terminal-Bench 2.1 (2026-06-30)80.4Not verifiedUnverified
Humanity's Last Exam (2026-06-30)57.4Not verifiedUnverified
SWE-bench Verified (2026-09-01)79.6Not verifiedUnverified
LiveBench (2026-09-05)76Not verifiedUnverified
DeepSWE 1.1 [max] (2026-09-22)Not verifiedUnverified68.8
OSWorld 2.0 (offline) [xhigh] (2026-09-22)Not verifiedUnverified60.5
Terminal-Bench 4.0 [max] (2026-09-26)Not verifiedUnverified43.9

Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Bold indicates the better figure where one is objectively better. Values we could not confirm from the provider are shown as “Not verified” rather than estimated.

Benchmark receipts

Where each score comes from, and how far it can be compared across models.

Pricing tiers

Claude Sonnet 5: Standard $2/$10 per MTok; cache reads 10% of base input. Knowledge cutoff Jan 2026.

GPT-6 Sol: Replaces GPT-5.6 Sol at 50% of its $4/$20 promo price. Cached input $0.20/MTok; cache writes $2.50 (1.25x). Above 272K input the whole request bills $4/$15 ($0.40 cached). Batch/Flex $1/$5; Fast mode $4/$20. Knowledge cutoff Apr 20 2026. Launched in the API, ChatGPT Work and Codex the same day.

BalancedRecord checked September 26, 2026

Claude Sonnet 5

Claude Sonnet 5 is Anthropic's best speed/intelligence balance for high-volume agentic work at $2/$10.

Best for

  • Everyday generation
  • High-volume agents
  • Cost-sensitive work

Watch out

A step below Opus 5.5 on the hardest tasks; pick Opus 5.5 when quality is paramount. Sonnet 5.5 is announced but not yet released.

BalancedRecord checked September 26, 2026

GPT-6 Sol

GPT-6 Sol brings GPT-6 Astra's training advances to OpenAI's mid-priced tier — OpenAI claims roughly half GPT-5.6 Sol's factual-error rate at half its price, with a 1.05M-token context.

Best for

  • Default OpenAI production model
  • Agentic coding
  • Long-context knowledge work

Watch out

Brand-new (2026-09-22): the DeepSWE figure is vendor-reported and it is not yet on the independent boards; long prompts above 272K bill $4/$15 for the whole request.

When the cheaper one wins

Both charge $10 per million output tokens at standard rates, so output price is not the split. Prefer the row whose “best for” line matches the job, then confirm the live vendor rate.

Run the model picker

Evidence confidence: High

How strong and complete the evidence behind this comparison is — not a prediction of which model is better.

  • Pricing verified on both sides — Input and output rates are verified for both models.
  • 4/5 core specs verified on both sides — Not published for at least one side: parameter count.
  • 1 shared named benchmark with differing scores — Measured on: Artificial Analysis Intelligence Index.
  • Verified within the last 90 days — Newest catalog check was 2 days ago.
  • Both models carry source citations — Each side has at least two catalog sources on record.

Source receipts

Each catalog figure was checked against the provider or an independent second source on the date shown.

Related comparisons

Diving deeper on one model? Claude Sonnet 5 · GPT-6 Sol

Common questions

Claude Sonnet 5 vs GPT-6 Sol

Answered from the verified figures on this page rather than general guidance.

Is Claude Sonnet 5 or GPT-6 Sol cheaper for input?
Both cost $2 per million input tokens at standard rates, so input price is not a deciding factor between them.
Is Claude Sonnet 5 or GPT-6 Sol cheaper for output?
Both cost $10 per million output tokens at standard rates, so output price is not a deciding factor between them.
Which has the larger context window, Claude Sonnet 5 or GPT-6 Sol?
GPT-6 Sol accepts 1.05M tokens against 1M for Claude Sonnet 5. This only matters if you routinely send very long documents or large codebases.
Do Claude Sonnet 5 and GPT-6 Sol support the same reasoning levels?
Claude Sonnet 5 exposes adaptive, while GPT-6 Sol exposes none, low, medium, high, xhigh, max.
Should I use Claude Sonnet 5 or GPT-6 Sol?
Both sit in the balanced tier, so the choice usually comes down to price and context rather than capability. Claude Sonnet 5 suits everyday generation; GPT-6 Sol suits default openai production model.

Next step

Choosing between them

The verified figures that separate this pair, computed from the catalog rather than restated boilerplate.

  • Context: GPT-6 Sol takes 1.05M against 1M for Claude Sonnet 5 — only decisive if your prompts approach the smaller window.
  • Measured capability: GPT-6 Sol leads Artificial Analysis Intelligence Index 47.5 to 38.2 (measured 2026-09-26).
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