GPT-4o mini vs GPT-5.5: pricing & cost comparison
On input tokens, GPT-4o mini is the cheaper of the two — 97% less per million ($0.15 vs $5). On output, GPT-4o mini is 98% cheaper ($0.6 vs $30) — and since output is usually the dominant cost driver, that gap matters more than it looks.
Side by side
| GPT-4o mini | GPT-5.5 | |
|---|---|---|
| Input / 1M tokens | $0.15 | $5 |
| Output / 1M tokens | $0.6 | $30 |
| Context window | 128,000 | 1,050,000 |
| Token-count accuracy | exact | exact |
| Cost — 10,000 input + 2,000 output tokens | $0.0027 | $0.11 |
What a real request costs
Take a representative turn — 10,000 input + 2,000 output tokens. GPT-4o mini comes to $0.0027, GPT-5.5 to $0.11. Across 100,000 requests that's a $10730 swing in favour of GPT-4o mini. To run the numbers on your actual prompt, paste it into the calculator and toggle Compare across all models.
Same vendor — an easy switch
Moving between GPT-4o mini and GPT-5.5 is a same-vendor move — one SDK, one tokenizer, so no recalibration. That makes this a straight cost/quality call: send the routine bulk of traffic to GPT-4o mini ($0.15/$0.6 per 1M) and reserve GPT-5.5 for the requests that visibly need its extra headroom. On the worked example above that split is worth about 98% per request — small per call, real money once you multiply by volume.
See the full breakdown on the dedicated pages for GPT-4o mini and GPT-5.5.
FAQ
- Is GPT-4o mini or GPT-5.5 cheaper?
- For a typical request (10,000 input + 2,000 output tokens), GPT-4o mini is cheaper — about 98% less, or roughly $10730 saved per 100,000 requests. GPT-4o mini runs $0.15/$0.6 per 1M input/output tokens; GPT-5.5 runs $5/$30.
- Which has the larger context window?
- GPT-5.5, at 1,050,000 tokens versus 128,000.
- How accurate are these token counts?
- GPT-4o mini: Exact tokenization via the canonical OpenAI vocab (o200k_base). GPT-5.5: Exact tokenization via the canonical OpenAI vocab (o200k_base). The dollar math itself is exact once the token count is known.
Both prices are computed from tokenmath's verified pricing table. Rates sourced from openai.com and developers.openai.com, verified 2026-07-06. Vendor pricing changes often — confirm before you commit.