Compare AI models

Specifications
Context window
1.05M—
API pricing
Input price
$5.00—
Output price
$30.00—
Cached input price
$0.50—
Cheapest input
$2.50OpenAI—
Cheapest output
$15.00OpenAI—
Benchmarks
BullshitBench v2
47%50%
Humanity's Last Exam · with tools
52.2%35%
Overview
CompanyOpenAISpaceXAI
Release dateApr 23 2026Apr 17 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

GPT-5.5 and Grok 4.3 Beta are evenly matched across the 2 benchmarks they both report (BullshitBench v2, Humanity's Last Exam). Only GPT-5.5 has a verified first-party API price: $5.00 per million input tokens and $30.00 per million output tokens. No pay-as-you-go API rate is tracked for Grok 4.3 Beta. Grok 4.3 Beta shipped 6 days before GPT-5.5, 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, Grok 4.3 Beta leads at 50% vs GPT-5.5 at 47%. On Humanity's Last Exam · with tools, GPT-5.5 leads at 52.2% vs Grok 4.3 Beta at 35%.