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.
1M128k
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.
$0.10—
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.
$0.50—
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.
$0.004—
$45.00Meta list price—
These models have no shared benchmark scores.
Overview
CompanyMetaOpenAI
Release dateNov 9 2026Feb 12 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Muse Ember and GPT-5.3-Codex-Spark don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Only Muse Ember has a verified first-party price for an available API: $0.10 per million input tokens and $0.50 per million output tokens. No currently available pay-as-you-go API rate is tracked for GPT-5.3-Codex-Spark. GPT-5.3-Codex-Spark shipped 270 days before Muse Ember, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Muse Ember) vs 128k (GPT-5.3-Codex-Spark).

Direct benchmark comparisons are unavailable — Muse Ember and GPT-5.3-Codex-Spark don't publish scores on any of the same benchmarks.