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Model comparisons

GPT 6.1 Sol vs Kimi K3.1 Pro

GPT 6.1 Sol or Kimi K3.1 Pro, tier by tier: matched prices, request fields, limits and the content policy measured on each.

GPT 6.1 Sol

GPT 6.1 Sol reviews difficult code changes and professional analyses with text and image evidence in one conversation. Sol’s 128,000-token reply budget includes reasoning as well as the patch or analysis you see; the default cap is 4,096.

View model details →View sample outputs →

Kimi K3.1 Pro

Kimi K3.1 Pro is Moonshot AI's flagship model, released on 23 October 2026 as the first model in its K3.1 series; Moonshot describes it as its most capable open-weight model to date. Here it is one OpenAI-compatible chat endpoint: up to 1,048,576 tokens of input, text, images and video in the messages, function calling, streaming, and a reasoning_effort of low, high or max on every request.

View model details →View sample outputs →

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The short answer

Start with the input you have, the result you want and your budget. These are the differences that affect that choice.

  • On the published fields these two sit close together. The tables below list every field where the catalogue records a difference at all.

Compare the published examples, then try the same input on both models with matching settings.

Test scores side by side

The Spicy Index and Freedom Score for both models, from the same daily calculation as the leaderboards.

Test scores side by side
MeasureGPT 6.1 SolKimi K3.1 Pro
Spicy Index81.280.4
Freedom ScoreNot yet testedNot yet tested
Evidence——
Range if the rest pass——
Price$4.00 per 1M mixed tokens (3 input : 1 output)$4.00 per 1M mixed tokens (3 input : 1 output)
ReviewsRead the GPT 6.1 Sol reviewRead the Kimi K3.1 Pro review

Preliminary · freedom evidence pending

See both on the leaderboard →

Current price

Price at the same setting

A start price answers a different question than the one you have. These are the tiers both models publish, matched setting for setting, in US dollars per billed unit with no conversion step in between.

Swipe horizontally to compare all fields.

Price at the same setting
TierGPT 6.1 SolKimi K3.1 ProDifference
Input$2 / 1 million tokens$2 / 1 million tokensIdentical
Cached input$0.1 / 1 million tokens$0.2 / 1 million tokensGPT 6.1 Sol −50%
Output$10 / 1 million tokens$10 / 1 million tokensIdentical

What one ordinary job costs

  • GPT 6.1 Sol: $4 for one million input and two hundred thousand output tokens.
  • Kimi K3.1 Pro: $4 for one million input and two hundred thousand output tokens.

Arithmetic on the published rates at each model's own default setting, not a quote. The console prices your actual settings before a request is accepted.

About this comparison

Controls and limits

Every row here is read from the JSON Schema the endpoint validates against, so it matches what the API will really accept rather than a feature list written by hand.

Swipe horizontally to compare all fields.

GPT 6.1 Sol vs Kimi K3.1 Pro
Controls and limitsGPT 6.1 SolKimi K3.1 Pro
Supported taskschatchat
Input context1,050,000 tokens1,048,576 tokens
Maximum output128,000 tokens1,048,576 tokens
Tool callingYesYes
ExecutionSynchronous, with streamingSynchronous, with streaming
Request timeout10 minutes10 minutes
AvailabilityLiveLive

Can I swap the model ID without changing the request body?

Request body, field by field

The task lifecycle is shared; the body is not. Each endpoint publishes its own JSON Schema and the API validates against that, so this is the list to reconcile before a switch.

  • 8 fields appear in both request bodies under the same names. stop, tools, messages, max_tokens, tool_choice, response_format, reasoning_effort, parallel_tool_calls
  • Only GPT 6.1 Sol accepts: top_p, temperature.
  • Kimi K3.1 Pro accepts no field the other one lacks.
  • GPT 6.1 Sol requires messages.
  • Kimi K3.1 Pro requires messages.
  • Both reject unknown fields outright, so a parameter left over from the other model comes back as a validation error instead of being quietly ignored.

How to choose

How to choose

Maximum output

Kimi K3.1 Pro can return more in one reply: up to 1,048,576 tokens against the other model's ceiling.

Input context

GPT 6.1 Sol takes the longer prompt: up to 1,050,000 input tokens in a single request.

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Moving from one to the other

The model identifiers are openai/gpt-6.1-sol/chat and moonshot/kimi-k3.1-pro/chat, and both go in the same field of the same request.

Both return the response on the chat request. With streaming enabled, read the stream until it finishes; there is no media task to poll.

Both use the same submit-and-track flow, but their required inputs may differ. Check each model page before switching.

One key, one balance, one set of spend caps. Both bill to the same account in US dollars, and the per-key daily, monthly and lifetime limits apply to whichever one you call.

Questions developers ask

Which is cheaper, GPT 6.1 Sol or Kimi K3.1 Pro?

Which is cheaper, GPT 6.1 Sol or Kimi K3.1 Pro?

Prices and capabilities shown here come from the current public model catalogue. Check each model page for its latest inputs and examples. Prices may change; check the estimate shown for your actual settings before submitting.

How long can a single request run?

GPT 6.1 Sol allows 10 minutes per task and Kimi K3.1 Pro allows 10. Those are ceilings rather than typical times — most requests finish far sooner — but they are what your own client timeout has to survive.

Prices and capabilities shown here come from the current public model catalogue. Check each model page for its latest inputs and examples.

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