| Input per 1M tokens | $1.75 |
| Output per 1M tokens | $14 |
| Cache read per 1M tokens | — |
| Status | active |
| Source | official pricing page · verified 2026-09-07 |
Coding-tuned.
Example costs
- One request (2,000 in / 500 out): $0.0105
- 100K such requests/month: $1,050
- 1M input + 1M output tokens: $15.75
Compare against other models →
How GPT-5.3 Codex compares on rate
GPT-5.3 Codex runs $1.75 input / $14 output per MTok — a combined $15.75 for 1M tokens each way. The cheapest active model in our table, Gemini 2.5 Flash-Lite at $0.1/$0.4 (combined $0.5), is about 97% cheaper on combined rate (verified 2026-09-07).
Cheapest active OpenAI alternative: GPT-5.6 Luna at $0.2/$1.2 per MTok — combined $1.4 against $15.75, about 91% less.
Per-token rate is not per-task cost — tokenizers differ between model families, so benchmark with your own payloads before switching.
What real volumes cost at GPT-5.3 Codex rates
Straight rate-card math at the verified $1.75/$14 per-MTok prices, assuming a 75% input / 25% output token split — no caching or batch discounts applied.
| Volume | Split | Cost at GPT-5.3 Codex rates |
|---|---|---|
| 100K tokens in a day | 75,000 in + 25,000 out | $0.4813 |
| That pace over a 30-day month (3M tokens) | 2.25M in + 750K out | $14.44 |
| 1M tokens in a month | 750,000 in + 250,000 out | $4.81 |
| Heavy month — 12M tokens | 9M in + 3M out | $57.75 |
Change the split or volume in the calculator — same verified rates, your numbers. Method + the corrections that make estimates real: how to estimate LLM API costs.
Frequently asked questions
What does GPT-5.3 Codex cost per million tokens?
GPT-5.3 Codex costs $1.75 per 1M input tokens and $14 per 1M output tokens on the OpenAI API (verified 2026-09-07).
How much does 100K tokens a day cost on GPT-5.3 Codex?
At a 75% input / 25% output split, 100K tokens costs about $0.4813 at GPT-5.3 Codex rates — about $14.44 over a 30-day month. That is straight rate-card math, before any caching or batch discounts.
Is there a cheaper model than GPT-5.3 Codex?
Yes — the cheapest active model we track is Gemini 2.5 Flash-Lite at $0.1/$0.4 per MTok, a combined $0.5 against GPT-5.3 Codex's $15.75 — about 97% less on combined rate (verified 2026-09-07). Tokenizers differ between families, so benchmark per-task cost with your own payloads.
How much do 1M input + 1M output tokens cost on GPT-5.3 Codex?
$15.75 — $1.75 for the input million plus $14 for the output million, at OpenAI rates verified 2026-09-07.