GPT-4o vs Grok 4
Complete pricing and performance comparison between OpenAI's GPT-4o and xAI's Grok 4.
Quick Verdict
Cheaper
GPT-4o
1.2x cheaper input, 1.5x cheaper output
Larger Context
Grok 4
2.0M vs 128K
Higher Quality
Grok 4
Score: 42 vs 17
Faster
GPT-4o
135 vs 49 tok/s
Pricing Comparison
| Spec | GPT-4o | Grok 4 | Difference |
|---|---|---|---|
| Provider | OpenAI | xAI | |
| Input / 1M tokens | $2.5 | $3 | GPT-4o is 17% more expensive |
| Output / 1M tokens | $10 | $15 | GPT-4o is 33% more expensive |
| Context Window | 128K | 2.0M | 16x difference |
| Max Output | 16K | 16K | |
| Tokenizer | o200k_base | cl100k_base |
Performance Benchmarks
| Metric | GPT-4o | Grok 4 | Winner |
|---|---|---|---|
| Quality Index | 17 | 42 | Grok 4 |
| Output Speed | 135 tok/s | 49 tok/s | GPT-4o |
| Time to First Token | 0.53s | 9.39s | GPT-4o |
| Value (Quality/$) | 6.9 | 13.8 | Higher = better value |
Benchmark data from Artificial Analysis. Quality Index is a composite score across reasoning, coding, and knowledge tasks.
Cost at Scale
Estimated cost at different usage levels (3:1 input-to-output token ratio, typical for chat).
| Usage | GPT-4o | Grok 4 | Savings |
|---|---|---|---|
Single request 1K in / 300 out | $0.0055 | $0.0075 | GPT-4o saves $0.0020 |
10 requests 10K in / 3K out | $0.055 | $0.075 | GPT-4o saves $0.020 |
100 requests 100K in / 30K out | $0.550 | $0.750 | GPT-4o saves $0.200 |
1,000 requests 1M in / 300K out | $5.50 | $7.50 | GPT-4o saves $2.00 |
10,000 requests 10M in / 3M out | $55.00 | $75.00 | GPT-4o saves $20.00 |
1M requests/mo 1B in / 300M out | $5500.00 | $7500.00 | GPT-4o saves $2000.00 |
Pros & Cons
GPT-4o Strengths
- +Cheaper input tokens
- +Cheaper output tokens
- +Faster output (135 vs 49 tok/s)
- +Lower latency (faster first token)
Grok 4 Strengths
- +Larger context window (2.0M vs 128K)
- +Higher quality score (42 vs 17)
When to Use Each Model
Choose GPT-4o for
- →Budget-conscious projects where cost is the primary factor
- →Real-time applications, chat, or autocomplete
Choose Grok 4 for
- →Long documents, large codebases, or multi-turn conversations
- →Tasks requiring maximum accuracy and reasoning
Frequently Asked Questions
Which is cheaper, GPT-4o or Grok 4?
For input tokens, GPT-4o is 1.2x cheaper at $2.5/1M tokens. For output tokens, GPT-4o is 1.5x cheaper at $10/1M tokens. At typical usage (1M input + 300K output), GPT-4o costs $5.50 vs Grok 4 at $7.50.
What's the context window difference?
GPT-4o supports 128K context (128,000 tokens), while Grok 4 supports 2.0M (2,000,000 tokens). Grok 4 can handle 16x more context in a single request.
Which model has better benchmarks?
Quality Index: GPT-4o scores 17 vs Grok 4 at 42. Speed: GPT-4o generates 135 tok/s vs Grok 4 at 49 tok/s. Time to first token: GPT-4o at 0.53s vs Grok 4 at 9.39s.
When should I choose GPT-4o over Grok 4?
Choose GPT-4o when you need: Cheaper input tokens, Cheaper output tokens, Faster output (135 vs 49 tok/s), Lower latency (faster first token). Choose Grok 4 when you need: Larger context window (2.0M vs 128K), Higher quality score (42 vs 17).
How much would 10,000 API requests cost?
At 1K input + 300 output tokens per request (typical chat): GPT-4o = $55.00, Grok 4 = $75.00. At 10K input + 1K output per request (longer conversations): GPT-4o = $350.00, Grok 4 = $450.00.