OpenAI API pricing for every GPT model, newest first

By TechCompare · Updated · How we check

A 50,000 token prompt with a 4,000 token answer and half the input cached costs $0.04625 on GPT-6.1 Terra, the newest model. GPT-5 Nano, the lowest cost model OpenAI sells itself, runs it for $0.002975.

Every OpenAI model and its API price

Newest first. Prices are per 1M tokens. One request is 50K tokens in and 4K out, with 50% of the input cached.

ModelInputOutputCachedContextOne requestListed
GPT-6.1 TerraOpenAI$1$5$0.051.05M$0.0462Oct 26, 2026
GPT-6.1 SolOpenAI$2$10$0.101.05M$0.0925Sep 29, 2026
GPT-6 LunaOpenAI$0.10$0.50$0.011.05M$0.0048Sep 22, 2026
GPT-6 SolOpenAI$2$10$0.201.05M$0.095Sep 22, 2026
GPT-6 AstraOpenAI$10$50$11.05M$0.475Sep 4, 2026
GPT-5.6 LunaOpenAI$0.20$1.20$0.021.05M$0.0103Jul 9, 2026
GPT-5.6 SolOpenAI$4$20$0.401.05M$0.19Jul 9, 2026
GPT-5.6 TerraOpenAI$2$12$0.201.05M$0.103Jul 9, 2026
GPT Chat LatestOpenAI$5$30$0.50400K$0.2575May 5, 2026
GPT-5.5OpenAI$5$30$0.501.05M$0.2575Apr 24, 2026
GPT-5.5 ProOpenAI$30$180$301.05M$2.22Apr 24, 2026
GPT-5.4 MiniOpenAI$0.75$4.50$0.075400K$0.0386Mar 17, 2026

Listed is the day OpenRouter added the model. Prices checked Nov 14, 2026.

OpenAI sells its GPT models through the OpenAI API, billed per token. That's separate from ChatGPT: a Plus or Pro subscription doesn't come with API credit. This page lists all 44 OpenAI models OpenRouter carries, newest first, at OpenAI's own price where OpenAI still sells the model.

The GPT-6 models come in four tiers. Luna is the fast one for chat, classification and other high volume work. Terra is the everyday model, Sol is the step up, and Astra is the flagship for long, demanding jobs. Right now GPT-6 Luna lists $0.10 input and $0.50 output per million tokens, GPT-6.1 Terra $1 and $5, GPT-6.1 Sol $2 and $10, and GPT-6 Astra $10 and $50.

Newest
GPT-6.1 Terra
$1 in, $5 out per 1M
Lowest cost per request
GPT-5 Nano
$0.003 for the request in the table
Largest context
GPT-6.1 Terra
1.05M tokens

Calculator

Cost Comparison

Based on 50,000 input tokens (50% cached), 4,000 output tokens, and 100 requests.Prices come live from OpenRouter at each maker's own price where it's listed. Temporary deals are left out.

Loading model prices

How to read the OpenAI prices

A row shows OpenAI's own price where OpenAI sells the model. Where it doesn't anymore, like some older Codex and GPT-4 snapshots, the row shows the host that charges least, which is often Microsoft Azure. Input and output are per million tokens.

The newer GPT models also come in a Pro mode, which thinks much longer before it answers. When a Pro mode bills the same rates per token as its base model, the table leaves it out, since its row would only repeat the same numbers. The thinking still bills as output, so a Pro call can cost several times what a normal one does. Price Pro on real answers, not on the table. Older Pro models with their own rates, like o3 Pro and GPT-5.5 Pro, keep their own rows.

GPT Chat Latest points at the Instant model ChatGPT uses for quick replies, at $5 input and $30 output per million. It follows ChatGPT's updates, so the model behind the name changes over time. Pin a dated model instead if your app needs answers that stay the same.

Caching needs no setup. OpenAI caches any prompt past 1,024 tokens on its own, and on GPT-6.1 Terra a cached token costs $0.05 per million, 95% off the normal input rate. Put the parts that never change first, like the system prompt and the tool list, and the user's message last, so the cache can match the start of each call.

Very long prompts cost extra. On GPT-6.1 Terra, a prompt past 272,000 tokens bills $2 input and $7.50 output per million. GPT-6.1 Terra also has the largest window in the family, 1.05M tokens.

Work that can wait goes through the Batch API, which returns results within 24 hours. On GPT-6.1 Terra that's $0.50 input and $2.50 output per million, 50% off input. Flex processing sits in between: normal API calls that cost less but answer slower and can be turned away when OpenAI is busy. The table shows standard rates only.

The gpt-oss models are open weight under the Apache 2.0 license, so many hosts run them. gpt-oss-120b shows Near AI, at $0.03 input and $0.15 output per million, and you can run it on your own GPUs instead.

Verdict

Start with GPT-6.1 Terra and run the same prompts through GPT-5 Nano, the lowest cost model OpenAI sells for the example request. If its answers pass your checks, use it for volume. If they don't, step up one tier, not straight to the top. Check the table for a retirement date before you build on an older model, since OpenAI retires snapshots on a schedule.

Use a Pro mode only where a better answer is worth paying for much longer thinking, and measure it per answer. Keep prompt prefixes stable for the cache, and send anything that can wait a day through the Batch API.

More LLM pricing scenarios

Frequently asked questions

How much does the OpenAI API cost?
It depends on the model. GPT-6.1 Terra, the newest, costs $1 per million input tokens and $5 per million output tokens. Across the GPT-6 tiers, GPT-6 Luna is $0.10 input, GPT-6.1 Terra is $1, GPT-6.1 Sol is $2 and GPT-6 Astra is $10. The table at the top has every model.
Is the OpenAI API included in ChatGPT Plus or Pro?
No. ChatGPT plans and the API are billed separately. The API charges per token on your OpenAI platform account, at the rates in the table, and a ChatGPT subscription adds no API credit.
Why aren't the Pro modes in the table?
A Pro mode is the same model set to think much longer before it answers. When it bills the same rates per token as the base model, its row would only repeat the base model's numbers, so the table leaves it out. The thinking tokens still bill as output, so a Pro call usually costs several times a normal one. Test it on your own prompts before you switch. Older Pro models with their own rates, like o3 Pro, stay in the table.
Does the OpenAI API cache prompts?
Yes, on its own. Any prompt past 1,024 tokens can hit the cache, with no setup and no write fee. On GPT-6.1 Terra a cached token costs $0.05 per million, 95% off the normal input rate.
What is gpt-oss?
OpenAI's open weight models, gpt-oss-120b and gpt-oss-20b, released under the Apache 2.0 license. Anyone can download and run them, so many hosts sell them. The table shows Near AI for gpt-oss-120b, at $0.03 input and $0.15 output per million.
Which OpenAI model has the largest context window?
GPT-6.1 Terra, the newest, has the largest window at 1.05M tokens. Past 272,000 prompt tokens, GPT-6.1 Terra bills $2 input and $7.50 output per million.
What does Last known price mean in the table?
It marks a model OpenRouter no longer serves. The row keeps the last price we saw, so you can compare an old invoice with what's on sale now.