Claude Opus 5.5 vs GPT-6.1 Sol for writing

Anthropic's Claude Opus 5.5 and OpenAI's GPT-6.1 Sol for writing, compared on the figures Alevr runs on: list prices, context window, speed and intelligence grades, and the plan that includes each.

Anthropic

Claude Opus 5.5

Anthropic's newest Opus: long-running agentic coding and knowledge work, always thinking.

Input / output per M
$4.00 / $20.00
Context
1M
In Alevr from
Pro

OpenAI

GPT-6.1 Sol

Near-Astra performance for complex work at a lower cost.

Input / output per M
$2.00 / $10.00
Context
1.05M
In Alevr from
Pro

Side by side.

Claude Opus 5.5 vs GPT-6.1 Sol for writing, figure by figure
Claude Opus 5.5GPT-6.1 Sol
LabAnthropicOpenAI
ReleasedSep 2026Sep 2026
Context window1,000,000 tokens1,050,000 tokens
Input, per M tokens$4.00$2.00
Cached input, per M tokens$0.20$0.10
Output, per M tokens$20.00$10.00
Intelligence grade9 / 10Catalog estimate9 / 10Catalog estimate
Speed grade4 / 10Catalog estimate5 / 10Catalog estimate
Adjustable thinkingYesYes
Reads imagesYesYes
Searches the web in AlevrYesYes
Drives agents and CodeYesYes
Included in Alevr fromPro€24 a month incl. VATPro€24 a month incl. VAT

Which to pick.

Each answer below is a comparison of the figures above, nothing more. Costs use a writing turn of 1,500 input and 2,000 output tokens.

For long drafts on a budgetGPT-6.1 Sol
At list prices, 1,000 requests of a writing turn of 1,500 input and 2,000 output tokens cost $46.00 on Claude Opus 5.5 and $23.00 on GPT-6.1 Sol. GPT-6.1 Sol is about 2.0× cheaper for this workload.
For nuanced, demanding writingNo clear difference
Both carry the same intelligence grade, 9 out of 10. Neither model has an Artificial Analysis measurement in Alevr's latest benchmark sync yet, so both grades are the catalog's estimates and may move when one lands.
For output-heavy workGPT-6.1 Sol
Writing is mostly output. Claude Opus 5.5 charges $20.00 and GPT-6.1 Sol $10.00 per million output tokens.
For quick back-and-forthGPT-6.1 Sol
GPT-6.1 Sol has the higher speed grade, 5 against 4 out of 10.
For long documentsNo clear difference
The context windows are close: 1M and 1.05M tokens.
On a smaller Alevr planNo clear difference
Both are included from Pro, €24 a month incl. VAT.

Pick Claude Opus 5.5

On these figures it does not come out ahead on any measure here. Its lab's own positioning is in the note above; in Alevr you can try both on the same prompt and judge the answers yourself.

Pick GPT-6.1 Sol

  • for long drafts on a budget
  • for output-heavy work
  • for quick back-and-forth

Use both in Alevr.

Alevr puts Claude, GPT, Gemini and 150+ models in one subscription, hosted in France. Both of these are included from Pro, €24 a month incl. VAT. Plans start at €10.80.

More comparisons

Where these figures come from

Prices are each lab's API list price in US dollars per million tokens, as recorded in the model catalog Alevr bills from. Cached input is the rate a prompt-cache hit is billed at. Alevr subscribers do not pay per token: each plan includes a monthly usage budget.

Intelligence and speed are Alevr's 1 to 10 grades. Where Artificial Analysis has measured a model, the grade is computed from its Intelligence Index and median output speed. A model it has not measured yet carries an estimate from the lab's positioning, and the page says so. The benchmark sync last ran on 22 September 2026.

The figures change when labs change their prices. These pages are rebuilt from the same catalog each time Alevr ships, so they match what the app shows.