o4 Mini API Pricing
OpenAI · context window 200K · prices updated 2026-09-15
Where o4 Mini sits on price
At $4.40 per million output tokens, o4 Mini is a mid tier model — 2.1× the median output price of $2.08, which puts it cheaper than 34% and pricier than 66% of the models we track. It sits 37th cheapest of the 92 OpenAI models we track. Output costs 4.0× input, the usual spread — trim both, starting with the answer length.
Cached input is 75% cheaper. On an input-heavy workload you need roughly a 33% 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 o4 Mini
These three workloads are the ones teams actually run on a mid-priced model — a $4.40/1M 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. | $0.0117 | $175 |
| Document pipeline — 10K docs/day (3K in / 500 out) Batch-friendly: no user waiting, so a ~50% batch discount usually applies. | $0.0055 | $1650 |
| Small app — 1K requests/day (500 in / 150 out) The baseline most side projects actually run at. | $0.0012 | $36.30 |
Model your exact traffic in the API cost calculator — it preloads o4 Mini with caching and batch options.
o4 Mini price history
o4 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).
o4 Mini vs GLM 5.3
The closest-priced alternative from another vendor is GLM 5.3 (Z.ai (GLM)) — priced within a rounding error on output, with $0.3 more per million input tokens. 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 GLM 5.3 pricing →Cheaper alternatives
More OpenAI models
Frequently asked questions
› How much does the o4 Mini API cost?
o4 Mini costs $1.10 per million input tokens and $4.40 per million output tokens, with cached input at $0.275 per million (75% cheaper). That works out to roughly 227,273 output tokens per dollar.
› What does the support chatbot workload cost on o4 Mini?
Support chatbot — 500 conversations/day (5K in / 1.4K out) costs about $0.0117 per request and $175 per month on o4 Mini. Conversation history re-sent each turn — the classic prompt-caching win.
› What does it cost to fill o4 Mini's 200K context window?
Sending 200K of input in a single request costs $0.22 at $1.10 per million tokens — before any output. With prompt caching that same fill drops to about $0.055 on repeat requests. This is why large context windows are cheap to advertise and expensive to actually use.
› Is o4 Mini worth the price?
o4 Mini sits in the middle of the market (37 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.