Grok Code Fast 1 vs OpenAI o3
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Grok Code Fast 1
xAI · Aug 2025
A speed-first coding model built for agentic IDE loops, popular as a cheap fast tier in Cursor and similar tools.
OpenAI o3
68.9OpenAI · Apr 2025
OpenAI's dedicated 2025 reasoning model that pioneered thinking-with-images and agentic tool use within chain-of-thought.
The verdict
Grok Code Fast 1 wins 1 of the 1 benchmarks these models share, against 0 for OpenAI o3. On price the gap is dramatic: Grok Code Fast 1 works out roughly 6.7x cheaper per blended million tokens. Grok Code Fast 1 also takes 256K of context versus 200K for OpenAI o3.
Benchmark head-to-head 1–0
Specs & pricing
| Grok Code Fast 1 | OpenAI o3 | |
|---|---|---|
| modhub Index | — | 68.9 |
| Input price / 1M | $0.2 | $2 |
| Output price / 1M | $1.5 | $8 |
| Context window | 256K | 200K |
| Max output | — | 100K |
| Open weights | no | no |
| Reasoning model | yes | yes |
| Multimodal input | text | text, image |
| Knowledge cutoff | Aug 2025 | May 2024 |
| Released | Aug 2025 | Apr 2025 |
| Example monthly cost* | $4.25 | $32.00 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, Grok Code Fast 1 or OpenAI o3?
- Grok Code Fast 1 wins 1 of the 1 benchmarks these models share, against 0 for OpenAI o3. On price the gap is dramatic: Grok Code Fast 1 works out roughly 6.7x cheaper per blended million tokens. Grok Code Fast 1 also takes 256K of context versus 200K for OpenAI o3.
- Which is cheaper, Grok Code Fast 1 or OpenAI o3?
- Grok Code Fast 1 costs $0.2/$1.5 per million input/output tokens, while OpenAI o3 costs $2/$8. For a typical workload of 10M input and 1.5M output tokens per month, that's $4.25 versus $32.00.
- Which model is better for coding, Grok Code Fast 1 or OpenAI o3?
- On SWE-bench Verified — the standard agentic-coding benchmark — Grok Code Fast 1 scores 70.8% versus 69.1% for OpenAI o3, making Grok Code Fast 1 the stronger pick for coding agents.