By the toolist.ai editors. Researched from public sources, not hands-on tested by toolist.ai. Updated November 3, 2026; prices checked November 3, 2026.

GPT-6.1 Sol vs Claude Sonnet 5.5

Verdict

At the same token prices ($2 in, $10 out and $0.10 cached per million), GPT-6.1 Sol has the edge on the Artificial Analysis scores: the two tie at 55 on the Intelligence Index at max effort, and Sol leads at each model's default effort (46 against 42), on HLE-Diamond (59% against 53%) and on Terminal-Bench-Science (58% against 53%). Claude Sonnet 5.5 leads Terminal-Bench 4.0 (64% against 56%) and measures faster output. Sol also offers paid Fast and Ultrafast modes.

Verdict based on published prices, limits and benchmarks, not on our own tests.

Choose GPT-6.1 Sol if

  • You want the higher score at the default effort: 46 against 42 on the Intelligence Index
  • You need a paid speed tier: Fast mode at double the standard price, Ultrafast at six times
  • Your work is scientific terminal work: 58% against 53% on Terminal-Bench-Science
  • You already pay for ChatGPT Plus, which includes GPT-6.1 Sol

Choose Claude Sonnet 5.5 if

  • You run terminal work: 64% against 56% on Terminal-Bench 4.0
  • Your prompts often pass 272,000 tokens, where OpenAI charges GPT-6.1 Sol twice the input rate and 1.5 times the output rate, and Anthropic adds no surcharge
  • You want faster output: 103 tokens a second at high effort against 55.9 for Sol at medium

Price

Input costs the same on both. Output costs the same on both.

Per million tokensGPT-6.1 SolClaude Sonnet 5.5
Input$2 source$2 source
Cached input$0.10 source$0.10 source
Output$10 source$10 source

GPT-6.1 Sol: Prompts over 272,000 input tokens are billed at twice the input rate and 1.5 times the output rate for the whole request. Batch and Flex processing cost half; Fast mode costs double and Ultrafast six times.

Claude Sonnet 5.5: Cache writes cost $2.50 per million tokens (5-minute cache) or $4 (1-hour cache). The Batch API costs half. There is no long-context surcharge and no fast mode.

Worked example: what a month costs

We priced three monthly workloads at the standard rates. The provider does not publish these figures.

WorkloadGPT-6.1 SolClaude Sonnet 5.5
Support chatbot
100,000 replies, each 3,000 input and 400 output tokens, no caching (300M in, 40M out)		 $1,000$1,000
Document Q&A
5,000 questions over the same 60,000-token document set (90% cache hits), 800 output tokens each (300M in, 4M out)		 $127$127
Coding agent
200 tasks, each 1.5 million input tokens (90% cache hits) and 50,000 output tokens (300M in, 10M out)		 $187$187

Price your own workload

ModelCost a month
GPT-6.1 Sol $150
Claude Sonnet 5.5 $150

Standard API prices, no batch or priority discounts. Cached input is billed at the cache-read price; cache-write charges are not included. Reasoning models bill their thinking as output tokens.

Limits and release dates

GPT-6.1 SolClaude Sonnet 5.5
ReleasedSeptember 29, 2026 sourceSeptember 28, 2026 source
Context window1,050,000 tokens source1,000,000 tokens source
Maximum output128,000 tokens source128,000 tokens source
Knowledge cutoffApril 30, 2026 sourceJune 2026 source
Input and outputText and images in; text out sourceText and images in; text out source
API model namegpt-6.1-solclaude-sonnet-5-5

Benchmarks

Scores as published by the provider or measured by Artificial Analysis; higher is better. A dash means no score was published.

BenchmarkGPT-6.1 SolClaude Sonnet 5.5
Artificial Analysis Intelligence Index
max effort		 55.0 source55.0 source
Intelligence Index at everyday effort 46.0 (medium effort, the API default) source42.0 (high effort, the API default) source
Terminal-Bench 4.0
max effort		 56.0% source64.0% source
HLE-Diamond
max effort		 59.0% source53.0% source
Terminal-Bench-Science 0.1
max effort		 58.0% source53.0% source
Output speed 55.9 tokens/s (medium effort, Artificial Analysis) source103 tokens/s (high effort, Artificial Analysis) source

Benchmark and speed data from Artificial Analysis where linked.

Read more

Sources