GPT-5.4 Mini API Pricing
OpenAI · context window 400K · prices updated 2026-09-15
Where GPT-5.4 Mini sits on price
At $4.50 per million output tokens, GPT-5.4 Mini is a mid tier model — 2.2× the median output price of $2.08, which puts it cheaper than 32% and pricier than 68% of the models we track. It sits 40th cheapest of the 92 OpenAI models we track. Output costs 6.0× more than input here, so anything that makes the model write less — tighter instructions, structured output, lower max_tokens — moves the bill more than trimming the prompt.
Cached input is 90% cheaper. On an input-heavy workload you need roughly a 28% cache-hit rate to take 25% off the input line — reachable for chatbots and agents that resend the same system prompt and history.
What real workloads cost on GPT-5.4 Mini
These three workloads are the ones teams actually run on a mid-priced model — a $4.50/1M model is not bought for the same job as one ten times the price.
| Workload | Per request | Per month |
|---|---|---|
| Support chatbot — 500 conversations/day (5K in / 1.4K out) Conversation history re-sent each turn — the classic prompt-caching win. | $0.01 | $151 |
| Document pipeline — 10K docs/day (3K in / 500 out) Batch-friendly: no user waiting, so a ~50% batch discount usually applies. | $0.0045 | $1350 |
| Long-context analysis — 200 runs/day (250K in / 4K out) Only possible on large-context models; input cost is nearly the whole bill. | $0.2055 | $1233 |
Model your exact traffic in the API cost calculator — it preloads GPT-5.4 Mini with caching and batch options.
GPT-5.4 Mini price history
GPT-5.4 Mini's price has not moved since we began tracking it on Aug 2, 2026 — 44 days of stability in a market where 78 of the 334 models we track have repriced over the same period, including 9 of OpenAI's own 92 models.
Change-points from our daily price snapshots (tracking since Aug 2, 2026; intraday moves between snapshots are not captured).
GPT-5.4 Mini vs Gemini 3.5 Flash (batch)
The closest-priced alternative from another vendor is Gemini 3.5 Flash (batch) (Google) — priced within a rounding error on output, with identical input pricing. When two models land this close on price, the decision is quality on your own workload, not the price sheet: run 50 real requests through both and compare.
See Gemini 3.5 Flash (batch) pricing →Cheaper alternatives
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Frequently asked questions
› How much does the GPT-5.4 Mini API cost?
GPT-5.4 Mini costs $0.75 per million input tokens and $4.50 per million output tokens, with cached input at $0.075 per million (90% cheaper). That works out to roughly 222,222 output tokens per dollar.
› What does the support chatbot workload cost on GPT-5.4 Mini?
Support chatbot — 500 conversations/day (5K in / 1.4K out) costs about $0.01 per request and $151 per month on GPT-5.4 Mini. Conversation history re-sent each turn — the classic prompt-caching win.
› What does it cost to fill GPT-5.4 Mini's 400K context window?
Sending 400K of input in a single request costs $0.3 at $0.75 per million tokens — before any output. With prompt caching that same fill drops to about $0.03 on repeat requests. This is why large context windows are cheap to advertise and expensive to actually use.
› Is GPT-5.4 Mini worth the price?
GPT-5.4 Mini sits in the middle of the market (40 of 92 by price within OpenAI). The honest test is a routing experiment: send the same 200 real requests to this model and to a tier below, and compare failure rate against the price gap — most teams find a majority of traffic never needed the pricier model.