Compare GPT 4o (free) 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 4o (free)
Grok 4.5This free model API comes from the OpenAI model deployed on Azure. To prevent abuse, the external content filter provided by Azure has been enforced, which will result in additional delays. If you want to experience the full version of the model API without filters, please use the paid version and request the model name ID without "-free".
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: 1523; GPT 4o (free): 1360 (LMArena coding leaderboard).
GPT 4o (free): 0.5s time to first token measured on AIHubMix; see the live performance charts above for how each model behaves across the day.
GPT 4o (free) accepts 1,047,576 and Grok 4.5 accepts 500,000 input tokens. Maximum output per request is 32,768 tokens on GPT 4o (free) and 500,000 tokens on Grok 4.5.
GPT 4o (free) at 72.3 tok/s and Grok 4.5 at 32.8 tok/s, measured as output throughput on AIHubMix — a separate metric from time to first token.
GPT 4o (free) accepts text and image input and supports tool calling, function calling, structured outputs and long context; Grok 4.5 accepts text and image input and supports thinking, tool calling, function calling, structured outputs and long context.
Yes. AIHubMix serves every model on this page behind one OpenAI-compatible endpoint, so switching between them is a one-line change to the model field — no second account, key or SDK.
Related model match-ups readers also look at.
AIHubMix