Model comparison
Grok 2 vs GPT-4o
- Input
- $2.00
- Output
- $10.00
- Context
- 131K
- Released
- 2024-08-20
- Input
- $5.00
- Output
- $15.00
- Context
- 128K
- Released
- 2024-05-13
Grok 2 and GPT-4o split the 4 benchmarks both report evenly; Grok 2 is cheaper on input tokens ($2 vs $5 per 1M, 2.5×); Grok 2 has the larger context window (131K vs 128K); Grok 2 ships open weights while GPT-4o is API-only.
Specs and pricing side by side
| Spec | Grok 2 | GPT-4o |
|---|---|---|
| Maker | xAI (Grok) | OpenAI |
| Released | 2024-08-20 | 2024-05-13 |
| Context window | 131K | 128K |
| Max output | not published | 16K |
| Input price | $2.00 | $5.00 |
| Output price | $10.00 | $15.00 |
| Parameters | 270B total · 115B active (mixture-of-experts) | Not disclosed |
| License | Grok 2 Community License Agreement (source-available) | Proprietary |
| Weights | Open weights | API only |
| Modalities | Text, Vision | Text, Image, Audio, Vision |
| Knowledge cutoff | not published | October 2023 |
Benchmarks both models report
| Benchmark | Grok 2 | GPT-4o |
|---|---|---|
| MMLU | 87.5% | 87.2% |
| GPQA | 56% | 49.9% |
| MATH | 76.1% | 76.6% |
| HumanEval | 88.4% | 91% |
Scores are as published by each maker or its cited source; harness, reasoning effort and date can differ between rows, so treat small gaps as ties. Sources are listed on each model page.
Which one should you pick?
Pick Grok 2 if…
- You care about MMLU, GPQA (it scores higher on 2 shared benchmarks).
- Cost matters: input tokens cost 2.5× less ($2 vs $5 per 1M).
- You need the longer context (131K vs 128K).
- You want to self-host or fine-tune (open weights, Grok 2 Community License Agreement (source-available)).
- Your use case is: general-purpose chat and reasoning assistants (Grok on X).
Pick GPT-4o if…
- You care about MATH, HumanEval (it scores higher on 2 shared benchmarks).
- You need Image / Audio input, which Grok 2 lacks.
- Your use case is: real-time voice assistants and conversational agents (Advanced Voice Mode).
FAQ
Which is better, Grok 2 or GPT-4o?
Grok 2 and GPT-4o split the 4 benchmarks both report evenly; Grok 2 is cheaper on input tokens ($2 vs $5 per 1M, 2.5×); Grok 2 has the larger context window (131K vs 128K); Grok 2 ships open weights while GPT-4o is API-only. The better pick depends on whether you value benchmark scores, price per token, context length or openness for your workload.
How much cheaper is Grok 2?
Grok 2: $2.00 input, $10.00 output. GPT-4o: $5.00 input, $15.00 output (list API prices as published by each maker).
What are the context windows of Grok 2 and GPT-4o?
Grok 2 offers 131K; GPT-4o offers 128K with up to 16K output.
Is Grok 2 newer than GPT-4o?
Grok 2 was released 2024-08-20; GPT-4o was released 2024-05-13.