Compare AI models

Specifications
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.
$5.00—
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.
$25.00—
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.
$0.50—
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.
$5.00Amazon Bedrock—
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
$25.00Amazon Bedrock—
$2,250Anthropic list price—
Benchmarks
Gray Swan IPI · k = 1Prompt injection robustness — Attackers hide malicious instructions inside content the AI reads — a web page, an email, a document — and try to hijack what it does. Gray Swan's indirect prompt injection benchmark measures how often such an attack succeeds when the attacker gets a single try. Lower is better.
0.5%2.9%
Gray Swan IPI · k = 10Prompt injection robustness — Attackers hide malicious instructions inside content the AI reads — a web page, an email, a document — and try to hijack what it does. This variant gives the attacker 10 tries and counts an attack as successful if any of them works. Lower is better.
4.1%14.3%
Gray Swan IPI · k = 15Prompt injection robustness — Attackers hide malicious instructions inside content the AI reads — a web page, an email, a document — and try to hijack what it does. This variant gives the attacker 15 tries and counts an attack as successful if any of them works. Lower is better.
5.5%16.5%
SWE-Bench ProAgentic coding — Can the AI fix real bugs in real software? It's handed actual problems from open-source projects and has to write code that genuinely solves them. Higher is better.
69.2%55%
SWE-Bench VerifiedCoding — Real coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better.
88.6%77.4%
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.
74.6%67.3%
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.
57.9%50.4%
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.
72.08%42.5%
OSWorld-VerifiedAgentic computer use — Can the AI actually operate a computer — clicking, typing, and using real apps — to finish tasks on its own? Higher is better.
83.4%53.3%
Overview
CompanyAnthropicMeta
Release dateMay 28 2026Apr 8 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Opus 4.8 leads Muse Spark on 9 of the 9 benchmarks they both report. Only Claude Opus 4.8 has a verified first-party API price: $5.00 per million input tokens and $25.00 per million output tokens. No pay-as-you-go API rate is tracked for Muse Spark. Muse Spark shipped 50 days before Claude Opus 4.8, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

On Gray Swan IPI · k = 1, Claude Opus 4.8 leads at 0.5% vs Muse Spark at 2.9%. On Gray Swan IPI · k = 10, Claude Opus 4.8 leads at 4.1% vs Muse Spark at 14.3%. On Gray Swan IPI · k = 15, Claude Opus 4.8 leads at 5.5% vs Muse Spark at 16.5%. On SWE-Bench Pro, Claude Opus 4.8 leads at 69.2% vs Muse Spark at 55%. On SWE-Bench Verified, Claude Opus 4.8 leads at 88.6% vs Muse Spark at 77.4%. On Terminal-Bench 2.1, Claude Opus 4.8 leads at 74.6% vs Muse Spark at 67.3%. On Humanity's Last Exam · with tools, Claude Opus 4.8 leads at 57.9% vs Muse Spark at 50.4%. On ARC-AGI-2, Claude Opus 4.8 leads at 72.08% vs Muse Spark at 42.5%. On OSWorld-Verified, Claude Opus 4.8 leads at 83.4% vs Muse Spark at 53.3%.