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.
1.05M1.05M
API pricingUSD per 1M tokens · lower wins · base tier
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it.
$2.50$2.00
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$12.00
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.
$0.25$0.20
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.
$1.25OpenAI$1.00OpenAI
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
$7.50OpenAI$6.00OpenAI
$1,250OpenAI list price$1,000OpenAI 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.
48%54%
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.
57.7%63.4%
ToolathlonGeneral tool use — Tests how well the AI uses everyday real-world tools and apps to get things done. Higher is better.
54.6%53.1%
BrowseCompWeb browsing — Can the AI browse the web and track down hard-to-find answers? Higher is better.
82.7%87.5%
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.
73.95%83.9%
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better.
92.8%92.9%
MMMU-Pro · with toolsMultimodal reasoning — multimodal understanding and reasoning with access to tools
82.1%82%
MMMU-ProMultimodal reasoning — A tougher version of MMMU — college-level questions that mix images, diagrams, and text together. Higher is better.
81.2%80.7%
MRCR v2 (8-needle) · 256K–512KLong context — mean match ratio for eight needles within the indicated context band
57.5%89.6%
MRCR v2 (8-needle) · 512K–1MLong context — mean match ratio for eight needles within the indicated context band
36.6%72.5%
Overview
CompanyOpenAIOpenAI
Release dateMar 5 2026Jun 26 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

GPT-5.6 Terra leads GPT-5.4 on 7 of the 10 benchmarks they both report. GPT-5.6 Terra is cheaper on both input and output: $2.00 vs $2.50 per million input tokens, and $12.00 vs $15.00 per million output tokens. Figures are base-tier rates. GPT-5.4 shipped 113 days before GPT-5.6 Terra, so benchmark comparisons should account for the intervening progress.

Context windows are 1.05M (GPT-5.4) vs 1.05M (GPT-5.6 Terra).

On BullshitBench v2, GPT-5.6 Terra leads at 54% vs GPT-5.4 at 48%. On SWE-Bench Pro, GPT-5.6 Terra leads at 63.4% vs GPT-5.4 at 57.7%. On Toolathlon, GPT-5.4 leads at 54.6% vs GPT-5.6 Terra at 53.1%. On BrowseComp, GPT-5.6 Terra leads at 87.5% vs GPT-5.4 at 82.7%. On ARC-AGI-2, GPT-5.6 Terra leads at 83.9% vs GPT-5.4 at 73.95%. On GPQA Diamond, GPT-5.6 Terra leads at 92.9% vs GPT-5.4 at 92.8%. On MMMU-Pro · with tools, GPT-5.4 leads at 82.1% vs GPT-5.6 Terra at 82%. On MMMU-Pro, GPT-5.4 leads at 81.2% vs GPT-5.6 Terra at 80.7%. On MRCR v2 (8-needle) · 256K–512K, GPT-5.6 Terra leads at 89.6% vs GPT-5.4 at 57.5%. On MRCR v2 (8-needle) · 512K–1M, GPT-5.6 Terra leads at 72.5% vs GPT-5.4 at 36.6%.