o3 vs o4-mini
Side-by-side comparison of o3 (OpenAI) and o4-mini (OpenAI). Exact API pricing per million tokens, context windows, output speed, and total cost on real-world prompts.
Specifications
| Spec | o3 | o4-mini |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Model id | o3 | o4-mini |
| Input price (per 1M tokens) | $2.00 | $1.10 |
| Output price (per 1M tokens) | $8.00 | $4.40 |
| Context window | 200,000 | 200,000 |
| Output speed (tokens/sec) | ~40 | ~80 |
| Tokenizer encoding | o200k_base | o200k_base |
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 | o3 | o4-mini | Cheaper |
|---|---|---|---|---|---|
| Short question + answer | 50 | 150 | $0.001300 | $0.000715 | o4-mini |
| Code review on one file | 500 | 1,500 | $0.013000 | $0.007150 | o4-mini |
| Long document summary | 5,000 | 500 | $0.014000 | $0.007700 | o4-mini |
| Heavy reasoning task | 2,000 | 8,000 | $0.068000 | $0.037400 | o4-mini |
| Full codebase analysis | 50,000 | 10,000 | $0.180000 | $0.099000 | o4-mini |
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 o3 for
No clear advantage on the data points we measure. Compare on your actual prompts.
Pick o4-mini for
- •output-heavy workloads — o4-mini is meaningfully cheaper per output token
- •input-heavy workloads — o4-mini is cheaper per input token
- •latency-sensitive UX — o4-mini streams faster (~80 vs ~40 tok/s)
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 o3 to o4-mini
# Before
model = "o3"
# After
model = "o4-mini"If the providers differ (OpenAI vs OpenAI), 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 →