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$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.
$25.00$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.
$0.50$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.
$5.00Amazon 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.
$25.00Amazon Bedrock$14.00Azure
$2,250Anthropic 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.
95%24%
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%85%
Next.js EvalsNext.js coding — Vercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better.
68%68%
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%64.7%
Overview
CompanyAnthropicOpenAI
Release dateMay 28 2026Feb 5 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Opus 4.8 leads GPT-5.3-Codex on 3 of the 4 benchmarks they both report (BullshitBench v2, SWE-Bench Verified, Next.js Evals, OSWorld-Verified). GPT-5.3-Codex is cheaper on both input and output: $1.75 vs $5.00 per million input tokens, and $14.00 vs $25.00 per million output tokens. GPT-5.3-Codex shipped 112 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 BullshitBench v2, Claude Opus 4.8 leads at 95% vs GPT-5.3-Codex at 24%. On SWE-Bench Verified, Claude Opus 4.8 leads at 88.6% vs GPT-5.3-Codex at 85%. On Next.js Evals, both models score 68%. On OSWorld-Verified, Claude Opus 4.8 leads at 83.4% vs GPT-5.3-Codex at 64.7%.