GPT-5.3 Chat
OpenAI · released Mar 3, 2026
- Type
- Proprietary
- Input
- $1.75
- Output
- $14.00
- Cached
- $0.17
List price · per 1M tokens · OpenAI at 128K context · source ↗
Our take
Written Aug 3, 2026GPT-5.3 Chat is OpenAI's flagship reasoning model, available only through hosted APIs with a 128,000-token request limit and broad multimodal input. Its strongest measured skill is coding, while creative writing lags well behind, and all tracked providers charge the same premium rate.
Choose this for coding tasks where leaderboard scores are your quality signal, or for hard-prompt reasoning at Elo 1471.4. Use it when you need enterprise hosting through Azure or OpenAI direct with identical pricing across providers. Skip it if you want to run models locally, if creative writing quality matters most, or if you need a cheaper tier.
The case for it
- Strongest measured skill is coding, with an Arena Coding Elo 62.4 points above its own overall text score.
- Minimal leaderboard drift: its Arena Text score moved less than a fifth of a point across two days.
- One known throughput figure of 39 tokens per second on OpenAI direct.
The case against it
- Creative writing is its weakest measured skill, sitting 90.1 points below its own coding score.
- Premium pricing with no cheaper tier discovered at any of the three tracked providers.
- Closed system with undisclosed scale: parameter count is not published and no licence is granted.
How good is it?
IntelligencePuzzles, maths, exam questions
Arena Text (overall)36th of 143 · 1448.7
CodingWriting and fixing code on its own
Arena Coding41st of 143 · 1496.7
Arena Coding is the only board that has scored it for this.
AgenticPlanning, calling tools, staying on task
Nobody we watch has scored GPT-5.3 Chat for this. We would take the rating from Arena Agent (IPS).
WritingWe do not rate this
Two boards come close and neither tests writing: Arena Creative Writing asks people which of two replies they prefer, and LiveBench Language tests whether a model understood a passage. So we show where GPT-5.3 Chat placed and give it no mark out of five.
These tests check whether a model follows instructions — a precondition for all the work above, but not a measure of how well that work is done, which is why they get no rating.
Every published score for this model6 scoresEvery figure we hold, from 6 boards, with who ran it and a link to the source — including the boards no rating above is built on.
Or rent it from someone else
Why this differs from the header. The strip above quotes OpenAI's own list price. This is the cheapest live offer at the widest standard context we hold, whoever is serving it — a reseller undercutting a lab is ordinary commerce, not an error.
- per 1M tokens
- $1.75 in / $14.00 out
- Context served
- 128K
- Throughput
- Not measured
| Provider | In / out per 1M tokens | Context | Throughput | Trains on prompts | Logs prompts | Zero retention |
|---|---|---|---|---|---|---|
| OpenRouter | $1.75 / $14.00 | 128K | not measured | Unknown | Unknown | Unknown |
| Microsoft Azure AI | $1.75 / $14.00 | 128K | not measured | No | No | Confirmed |
| OpenAI | $1.75 / $14.00 | 128K16K out | 39 tok/s | No | Yesunknown period | Unknown |
Microsoft Azure AIAcross the 3 listings we hold: 2 say they do not train on prompts, 0 say they do and 1 do not say. 1 appear in the zero-retention registry we check; the rest are unknown to us rather than confirmed either way.
What each host's API supports
From the parameter list each endpoint publishes. Streaming is omitted: nothing we hold reports it, for any model.
- ✓
- Supported
- ✗
- Not supported
- Not published
- host gave no parameter list
| Provider | Tool calling | JSON output | Strict schema |
|---|---|---|---|
| OpenRouter | ✓ | ✓ | ✓ |
| Microsoft Azure AI | ✓ | ✓ | ✓ |
| OpenAI | ✓ | ✓ | ✓ |
Tool calling: 3 of 3 listings say yes. JSON output: 3 of 3 listings say yes. Strict schema: 3 of 3 listings say yes.
Models people weigh against GPT-5.3 Chat
When we formed this view
Dates behind this page
Prices last checked 8d ago
What we do not know about this model yet
- Nothing we hold says whether an endpoint streams, so we do not show it either way.
- 1 of 3 listings do not say whether they train on prompts.
Licence and identifiers
What the licence allowsWe hold no licence record for this model. Inside are the identifiers you need to pull it — its Hugging Face repo where we have one, our slug and a machine-readable card.
Licence
Commercial API terms. We hold no licence record for this model, so there is nothing to summarise here.
Identifiers
- Modality record
- text+image+file->text
- Catalogue slug
- openai-gpt-5-3-chat