Compare GPT-5.3-Codex from OpenAI and Grok 4.5 from Grok on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the AIHubMix API.
GPT-5.3-Codex
Grok 4.5GPT-5.3-Codex is optimized for agentic coding tasks in Codex or similar environments. GPT-5.3-Codex supports low, medium, high, and xhigh reasoning effort settings. If you want to learn more about prompting GPT-5.3-Codex, refer to our dedicated guide.
Grok 4.5 was trained on datasets spanning knowledge in coding, science, engineering, and math. With both intelligent and efficient reasoning, Grok 4.5 excels at real engineering tasks and exceeds comparable leading models at these tasks.
Prices are per million tokens. Time to First Token and throughput are rolling averages measured on AIHubMix.
Promotional prices show the discounted rate; see each model page for promotion windows.
Daily traffic served through AIHubMix — how demand for each model is trending.
Measured on real AIHubMix traffic, hourly buckets. Gaps mean no traffic in that hour.
LMArena ratings by capability (Bradley-Terry, commonly called Elo). Higher is better.
Source: LMArena (arena.ai) leaderboard, imported by AIHubMix. Models without published ratings are omitted per chart.
Estimate your monthly bill for the same workload on each model.
Monthly = daily × 30. Discounted rates applied where a promotion is active.
Grok 4.5: $6.00/M output tokens; GPT-5.3-Codex: $14.00/M. Use the cost calculator above to estimate your own workload.
Grok 4.5: 1.6s time to first token measured on AIHubMix; see the live performance charts above for how each model behaves across the day.
GPT-5.3-Codex accepts 400,000 and Grok 4.5 accepts 500,000 input tokens. Maximum output per request is 128,000 tokens on GPT-5.3-Codex and 500,000 tokens on Grok 4.5.
GPT-5.3-Codex at 60.2 tok/s and Grok 4.5 at 27.4 tok/s, measured as output throughput on AIHubMix — a separate metric from time to first token.
GPT-5.3-Codex accepts text and image input and supports thinking, function calling and structured outputs; Grok 4.5 accepts text and image input and supports thinking, tool calling, function calling, structured outputs and long context.
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