GPT-5 vs o4-mini

Side-by-side comparison of GPT-5 (OpenAI) and o4-mini (OpenAI). Exact API pricing per million tokens, context windows, output speed, and total cost on real-world prompts.

Specifications

Spec GPT-5 o4-mini
Provider OpenAI OpenAI
Model id gpt-5 o4-mini
Input price (per 1M tokens) $1.25 $1.10
Output price (per 1M tokens) $10.00 $4.40
Context window 400,000 200,000
Output speed (tokens/sec) ~110 ~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 GPT-5 o4-mini Cheaper
Short question + answer 50 150 $0.001563 $0.000715 o4-mini
Code review on one file 500 1,500 $0.015625 $0.007150 o4-mini
Long document summary 5,000 500 $0.011250 $0.007700 o4-mini
Heavy reasoning task 2,000 8,000 $0.082500 $0.037400 o4-mini
Full codebase analysis 50,000 10,000 $0.162500 $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 GPT-5 for

  • tasks needing a larger context window — gpt-5 fits 2x more tokens than o4-mini
  • latency-sensitive UX (chat, autocompletion) — gpt-5 streams faster (~110 vs ~80 tok/s)

Pick o4-mini for

  • output-heavy workloads — o4-mini is meaningfully cheaper per output token
  • complex multi-step reasoning — o4-mini uses chain-of-thought internally

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 to o4-mini

# Before
model = "gpt-5"

# 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 →