Compare AI models

Specifications
Context windowHow much information the model can work with in one request, measured in tokens — pieces of words or other data. This includes your question, attachments, conversation and reply. Limits can vary by model variant and provider.
1M400k
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.
$2.00$1.75
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.
$10.00$14.00
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.
$0.10$0.175
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.
$2.00Amazon Bedrock$1.75Azure
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
$10.00Amazon Bedrock$14.00Azure
$900Anthropic list price$1,050OpenAI list price
Benchmarks
BullshitBench v2Nonsense detection — Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better.
60%24%
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.
81.3%56.8%
threejsevalCommunity preference (Three.js) — Every model gets the same prompt — "the Eiffel Tower", "a glass fishbowl", "a robot arm picking toys into a box" — and builds a 3D scene in Three.js. Real people then see two scenes side by side, names hidden, and vote for the one they prefer. The votes become a chess-style Elo rating on threejseval.com, averaged across all the prompts. It measures whether the scene looks and moves right to a human eye, not whether the code passes a test. Higher is better.
18291153
Overview
CompanyAnthropicOpenAI
Release dateSep 28 2026Feb 5 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Sonnet 5.5 leads GPT-5.3-Codex on 3 of the 3 benchmarks they both report (BullshitBench v2, SWE-Bench Pro, threejseval). GPT-5.3-Codex is cheaper on input: $1.75 vs $2.00 per million tokens. Claude Sonnet 5.5 is cheaper on output: $10.00 vs $14.00 per million tokens. GPT-5.3-Codex shipped 235 days before Claude Sonnet 5.5, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Claude Sonnet 5.5) vs 400k (GPT-5.3-Codex).

On BullshitBench v2, Claude Sonnet 5.5 leads at 60% vs GPT-5.3-Codex at 24%. On SWE-Bench Pro, Claude Sonnet 5.5 leads at 81.3% vs GPT-5.3-Codex at 56.8%. On threejseval, Claude Sonnet 5.5 leads at 1829 vs GPT-5.3-Codex at 1153.