OpenAI o3
openai-o3OpenAI's o3 reasoning model. Spends compute on a private chain of thought before answering, strong at math, science and hard coding problems that benefit from deliberate reasoning.
- Price · 1M in / out
- US$2.40 / US$9.60
- Context
- 200,000 tokens
- Max. output
- 100,000 tokens
- Input → output
- Text + Image → Text
- Developer
- OpenAI
- Updated
- 23 September 2026
The provider is phasing this model out.
Playground
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This run
at most US$0.0099 · 0.99 credits reserved
Billed by the tokens actually used; the unused part of the reservation is refunded.
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Usable 24 hours after sign-up, up to 5 runs per day and at most 2 credits per run. Other sign-in methods start without credits. Enough for 10 runs of this model.
About OpenAI o3
OpenAI o3 is a model by OpenAI in the Text & chat category. On Railwail, OpenAI o3 costs US$2.40 per 1M input tokens and US$9.60 per 1M output tokens. The context window holds 200,000 tokens, and one response can be up to 100,000 tokens long.
Pricing
| Input | US$2.40 / 1M tokens |
|---|---|
| Output | US$9.60 / 1M tokens |
- Billed by the tokens each request actually uses.
- 1 credit = US$0.01
Cost calculator
Price calculator
Total
US$0.72
72 credits
Per request
US$0.0072 · 0.72 credits
Each request is rounded up to 0.01 credits.
API
curl https://railwail.com/api/v1/chat/completions \
-H "Authorization: Bearer $RAILWAIL_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "openai-o3",
"messages": [
{
"role": "user",
"content": "Explain what a vector database is in two sentences."
}
],
"max_tokens": 1024
}'import os
from openai import OpenAI
client = OpenAI(
api_key=os.environ["RAILWAIL_API_KEY"],
base_url="https://railwail.com/api/v1",
)
completion = client.chat.completions.create(
model="openai-o3",
messages=[
{
"role": "user",
"content": "Explain what a vector database is in two sentences.",
},
],
max_tokens=1024,
)
print(completion.choices[0].message.content)import OpenAI from "openai";
const client = new OpenAI({
apiKey: process.env.RAILWAIL_API_KEY,
baseURL: "https://railwail.com/api/v1",
});
const completion = await client.chat.completions.create({
model: "openai-o3",
messages: [
{
role: "user",
content: "Explain what a vector database is in two sentences."
}
],
max_tokens: 1024
});
console.log(completion.choices[0].message.content);// npm install railwail
import railwail from "railwail";
const rw = railwail(process.env.RAILWAIL_API_KEY);
const res = await rw.chat("openai-o3", [
{ role: "user", content: "Explain what a vector database is in two sentences." },
], { max_tokens: 1024 });
console.log(res.choices[0].message.content);Specifications
- Model ID
openai-o3- Developer
- OpenAI
- Category
- Text & chat
- Input
- Text, Image
- Output
- Text
- Context window
- 200,000 tokens
- Max. output
- 100,000 tokens
- Billing
- By usage (tokens or GPU time)
- Lifecycle
- Deprecated
- Catalog entry updated
- 23 September 2026
Tags
- openai
- o-series
- reasoning
- stem
- vision
Use cases
Frequently asked questions
What is OpenAI o3?
OpenAI o3 is a model by OpenAI in the Text & chat category. On Railwail you can call it with an API key through the Railwail API.
How much does OpenAI o3 cost on Railwail?
On Railwail, OpenAI o3 costs US$2.40 per 1M input tokens and US$9.60 per 1M output tokens. You are charged for what each request actually uses. Usage is paid from prepaid credits; 1 credit equals US$0.01.
What is the context window of OpenAI o3?
The context window of OpenAI o3 holds 200,000 tokens. One response can be up to 100,000 tokens long.
How fast is OpenAI o3?
There are not enough measured runs of OpenAI o3 on Railwail yet to state a run time. It depends on the input, the settings and the load at the provider.
Is OpenAI o3 better than Claude Fable 5.1?
That depends on the task. OpenAI o3 (OpenAI) and Claude Fable 5.1 (Anthropic) are both models in the Text & chat category. The comparison page shows their prices and specifications side by side.
Compare OpenAI o3 and Claude Fable 5.1Can OpenAI o3 process images?
Yes. OpenAI o3 accepts images as input in addition to text.
How do I use OpenAI o3 through the API?
Create a Railwail API key and send your request with the model ID openai-o3. Code examples for curl, Python and JavaScript are in the API section of this page.
Comparable models
All in this category- Claude Fable 5.1Anthropic
Anthropic's model for the most demanding reasoning and long-horizon agentic work. 1M-token context window, up to 128K output tokens, adaptive thinking that is always on.
- Claude Opus 4.8Anthropic
The most capable model of Anthropic's Opus 4 series. State of the art on long-horizon agentic work, coding and knowledge tasks, with a 1M-token context window at standard pricing.
- Claude Opus 5.5Anthropic
Anthropic's current Opus model for long-running agentic coding and knowledge work. 1M-token context window, up to 128K output tokens, adaptive thinking that is always on.
Use OpenAI o3 via the API
One API key for every model on Railwail. Usage is charged from prepaid credits, 1 credit = US$0.01.