GPT-5.4 vs Grok 4.20
Side-by-side comparison of GPT-5.4 (OpenAI) and Grok 4.20 (xAI). Exact API pricing per million tokens, context windows, output speed, and total cost on real-world prompts.
Specifications
| Spec | GPT-5.4 | Grok 4.20 |
|---|---|---|
| Provider | OpenAI | xAI |
| Model id | gpt-5.4 | grok-4.20 |
| Input price (per 1M tokens) | $2.50 | $2.00 |
| Output price (per 1M tokens) | $15.00 | $6.00 |
| Context window | 400,000 | 2,000,000 |
| Output speed (tokens/sec) | ~100 | ~75 |
Cost on real prompts
Total cost = (input tokens × input price) + (output tokens × output price). Numbers below use the exact pricing tables published by each provider.
| Scenario | Input | Output | GPT-5.4 | Grok 4.20 | Cheaper |
|---|---|---|---|---|---|
| Short question + answer | 50 | 150 | $0.002375 | $0.001000 | Grok 4.20 |
| Code review on one file | 500 | 1,500 | $0.023750 | $0.010000 | Grok 4.20 |
| Long document summary | 5,000 | 500 | $0.020000 | $0.013000 | Grok 4.20 |
| Heavy reasoning task | 2,000 | 8,000 | $0.125000 | $0.052000 | Grok 4.20 |
| Full codebase analysis | 50,000 | 10,000 | $0.275000 | $0.160000 | Grok 4.20 |
Want the exact cost for your prompt instead of these examples? Open the cost calculator pre-loaded with both models →
When to pick which
Heuristics derived from the spec table above. Always validate on your own prompts before committing — these are starting points, not verdicts.
Pick GPT-5.4 for
- •latency-sensitive UX (chat, autocompletion) — gpt-5.4 streams faster (~100 vs ~75 tok/s)
Pick Grok 4.20 for
- •output-heavy workloads — grok-4.20 is meaningfully cheaper per output token
- •input-heavy workloads — grok-4.20 is cheaper per input token
- •tasks needing a larger context window — grok-4.20 fits 5x more tokens than gpt-5.4
Switching between them
For most use cases, switching providers means updating the model id and the request shape if the providers differ. Within the same provider, it's usually a single-line change.
From GPT-5.4 to Grok 4.20
# Before
model = "gpt-5.4"
# After
model = "grok-4.20"If the providers differ (OpenAI vs xAI), you'll also need to swap the SDK / endpoint URL. Cross-provider migrations usually take 30 minutes to a few hours depending on how many features (streaming, function calling, tool use) you depend on.
Calculate cost on your own prompt
The examples above use generic input/output ratios. For an exact comparison, paste your real prompt into the calculator — it counts tokens with the right tokenizer for each model and shows side-by-side cost.
Open the calculator with both models →