Compare AI models

Specifications
ParametersA rough measure of how big the model is. More parameters usually means more capable and more expensive to run, though it is a poor guide on its own — a smaller, newer model often beats a larger, older one.
—2.8T
Context windowHow much text the model can hold in mind at once — your question, any documents you attach, the conversation so far, and its own reply. Go past it and the earliest part falls out of view.
—1M
API pricingUSD per 1M tokens · lower wins
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it.
—$3.00
Output priceWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one.
—$15.00
Cached input priceA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again.
—$0.30
Cheapest inputLowest input rate across every provider on OpenRouter, the lab included. The cheapest endpoint may run a quantised build or a shorter context — see "Available from" on the model page.
—$0.496Relace
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
—$9.50Chutes
—$640Wafer
Benchmarks
DeepSWE 1.1Agentic coding — Artificial Analysis' independent test of deep, agentic software-engineering work — the AI has to plan and carry out substantial coding tasks end to end. (Version 1.1 of the test.) Higher is better.
10%69%
Terminal-Bench 2.1Agentic terminal coding — Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? Higher is better.
67.3%88.3%
MCP AtlasMulti-step tool use — Can the AI chain together many tools and steps to complete one bigger task, rather than doing just a single thing? Higher is better.
82.2%84.2%
JobBenchProfessional tool use — Tests the AI on professional workplace tasks that require using real work tools — the kind of multi-step jobs an office worker handles. Higher is better.
17%52.9%
Toolathlon-VerifiedPersonal tool use — Tests how well the AI uses everyday personal tools and apps to get things done — a human-checked version of Toolathlon. Higher is better.
49.4%73.2%
Humanity's Last Exam · with toolsMultidisciplinary reasoning — Humanity's Last Exam — extremely hard expert questions across many subjects. “With tools” means the AI is allowed to search the web or run code while answering. Higher is better.
50.4%56%
ARC-AGI-2Abstract reasoning — Puzzle-style tests of abstract reasoning and pattern-finding — the kind of thing people find easy but AIs often struggle with. Higher is better.
42.5%60.4%
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better.
89.5%93.5%
CharXiv ReasoningChart reasoning — Can the AI read and reason about complex charts and figures, not just text? Higher is better.
88.9%84.8%
Overview
CompanyMetaMoonshot AI
Release dateApr 8 2026Jul 16 2026
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

Kimi K3 leads Muse Spark on 8 of the 9 benchmarks they both report. Only Kimi K3 has a verified first-party API price: $3.00 per million input tokens and $15.00 per million output tokens. No pay-as-you-go API rate is tracked for Muse Spark. Muse Spark shipped 99 days before Kimi K3, so benchmark comparisons should account for the intervening progress.

Muse Spark is closed, while Kimi K3 is open weight.

On DeepSWE 1.1, Kimi K3 leads at 69% vs Muse Spark at 10%. On Terminal-Bench 2.1, Kimi K3 leads at 88.3% vs Muse Spark at 67.3%. On MCP Atlas, Kimi K3 leads at 84.2% vs Muse Spark at 82.2%. On JobBench, Kimi K3 leads at 52.9% vs Muse Spark at 17%. On Toolathlon-Verified, Kimi K3 leads at 73.2% vs Muse Spark at 49.4%. On Humanity's Last Exam · with tools, Kimi K3 leads at 56% vs Muse Spark at 50.4%. On ARC-AGI-2, Kimi K3 leads at 60.4% vs Muse Spark at 42.5%. On GPQA Diamond, Kimi K3 leads at 93.5% vs Muse Spark at 89.5%. On CharXiv Reasoning, Muse Spark leads at 88.9% vs Kimi K3 at 84.8%.