Model comparisons
GPT 6.1 Terra bills 50% less than Kimi K3.1 Pro per million output tokens. Tier prices, request fields and limits side by side.
GPT 6.1 Terra reads screenshots and documents, then turns the supplied evidence into concise drafts or extracted fields. Terra defaults to a 4,096-token reply cap and permits 128,000; reserve part of that allowance for reasoning whenever effort is above none.
View model details →View sample outputs →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 →Compare
Start with the input you have, the result you want and your budget. These are the differences that affect that choice.
Compare the published examples, then try the same input on both models with matching settings.
The Spicy Index and Freedom Score for both models, from the same daily calculation as the leaderboards.
| Measure | GPT 6.1 Terra | Kimi K3.1 Pro |
|---|---|---|
| Spicy Index | 79.9 | 80.4 |
| Freedom Score | Not yet tested | Not yet tested |
| Evidence | — | — |
| Range if the rest pass | — | — |
| Price | $2.00 per 1M mixed tokens (3 input : 1 output) | $4.00 per 1M mixed tokens (3 input : 1 output) |
| Reviews | Read the GPT 6.1 Terra review | Read the Kimi K3.1 Pro review |
Preliminary · freedom evidence pending
See both on the leaderboard →Current price
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.
| Tier | GPT 6.1 Terra | Kimi K3.1 Pro | Difference |
|---|---|---|---|
| Input | $1 / 1 million tokens | $2 / 1 million tokens | GPT 6.1 Terra −50% |
| Cached input | $0.05 / 1 million tokens | $0.2 / 1 million tokens | GPT 6.1 Terra −75% |
| Output | $5 / 1 million tokens | $10 / 1 million tokens | GPT 6.1 Terra −50% |
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
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.
| Controls and limits | GPT 6.1 Terra | Kimi K3.1 Pro |
|---|---|---|
| Supported tasks | chat | chat |
| Input context | 1,050,000 tokens | 1,048,576 tokens |
| Maximum output | 128,000 tokens | 1,048,576 tokens |
| Tool calling | Yes | Yes |
| Execution | Synchronous, with streaming | Synchronous, with streaming |
| Request timeout | 10 minutes | 10 minutes |
| Availability | Live | Live |
Can I swap the model ID without changing the request body?
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.
How to choose
Kimi K3.1 Pro can return more in one reply: up to 1,048,576 tokens against the other model's ceiling.
GPT 6.1 Terra takes the longer prompt: up to 1,050,000 input tokens in a single request.
Compare
The model identifiers are openai/gpt-6.1-terra/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
GPT 6.1 Terra costs 50% less per million output tokens. Compare the input and cache rates below for longer conversations. Prices may change; check the estimate shown for your actual settings before submitting.
GPT 6.1 Terra 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.