OpenAI API Pricing (2026): GPT-6 Astra, GPT-6.1 Sol, GPT-6 Luna and the Full Per-Token Table

OpenAI API pricing for October 2026: gpt-6-astra costs $10.00/1M input, $1.00 cached, $50.00 output. gpt-6.1-sol is $2.00/$0.10/$10.00 and gpt-6-luna is $0.10/$0.01/$0.50. Batch and Flex halve every rate, Fast mode doubles them. Full per-token table, cache-write and long-context rates, monthly cost scenarios, and the ChatGPT Plus breakeven.

June 18, 2026 ยท 2 min read
OpenAI API Pricing (2026): GPT-6 Astra, GPT-6.1 Sol, GPT-6 Luna and the Full Per-Token Table

Last updated: October 15, 2026. Every rate on this page was checked against OpenAI's official pricing docs (developers.openai.com) on that date.

Quick answer

The flagship gpt-6-astra costs $10.00/1M input, $1.00/1M cached input, and $50.00/1M output. The mid-tier gpt-6.1-sol is $2.00/$10.00 and the budget gpt-6-luna is $0.10/$0.50 per million input/output. Batch and Flex bill at half those rates. Fast mode doubles them. Long-context requests bill a higher second rate.

OpenAI bills the API per token. As of October 15, 2026, the pricing page leads with the GPT-6 family: gpt-6-astra at $10.00/1M input, $1.00/1M cached input, and $50.00/1M output, gpt-6.1-sol at $2.00/$10.00, and gpt-6-luna at $0.10/$0.50. A new cache-writes column bills the first write of a cached prefix at 1.25x the input rate.

$10.00/1M
gpt-6-astra input tokens
$50.00/1M
gpt-6-astra output tokens
$0.10/1M
gpt-6-luna input (cheapest flagship row)
95%
gpt-6.1-sol cached input discount

The Current OpenAI API Price Table

The table below is the current OpenAI API lineup as listed on the official pricing page, in USD per million tokens at the Standard tier, short-context rate. Input is the cost to send tokens to the model. Cached input is the discounted rate for a repeated prompt prefix. Cache writes bill the first time a prefix is stored. Output is the cost of generated tokens. All figures verified October 15, 2026.

OpenAI API pricing per 1M tokens (Standard tier, verified Oct 15, 2026)
ModelInputCached inputCache writesOutput
gpt-6-astra (flagship)$10.00$1.00$12.50$50.00
gpt-6.1-sol$2.00$0.10$2.50$10.00
gpt-6-luna$0.10$0.01$0.125$0.50
gpt-5.6-sol (Cyber, promo)$4.00$0.40$5.00$20.00
gpt-5.6-cyber$12.50$1.25$15.625$75.00
gpt-5.3-codex$1.75$0.175n/a$14.00
Reading the table

gpt-6.1-sol costs 20% of gpt-6-astra on input and output. gpt-6-luna costs 5% of gpt-6.1-sol. gpt-5.6-sol now sits under OpenAI's Cyber models heading at a promotional rate available at least through November 21, 2026. gpt-5.6-cyber is the Daybreak security model. gpt-5.3-codex keeps its $1.75/$14.00 rate.

The spread across the lineup is wide. gpt-6-luna output at $0.50/1M versus gpt-6-astra output at $50.00/1M is a 100x difference. Matching the model to the task beats defaulting every call to the flagship.

How OpenAI Token Pricing Works

OpenAI charges per token, not per request. A token is roughly 4 characters of English text, so 1,000 tokens is about 750 words. Every API call has an input token count (your prompt plus conversation history plus any tool schemas) and an output token count (the model's response). You pay for both at different rates.

Output costs 5x input on all three GPT-6 models. gpt-6-astra charges $10.00/1M input and $50.00/1M output. gpt-6.1-sol charges $2.00/1M input and $10.00/1M output. This asymmetry means a read-heavy workload (summarizing a large document, answering questions about code) is far cheaper than a generation-heavy workload (writing new files, producing long completions) at the same total token count.

Two more dimensions multiply on top of the base rate: the processing tier (Batch halves rates, Fast mode doubles them) and context length (long-context requests bill a higher second rate). Both are covered below.

Input tokens

Everything you send: the prompt, conversation history, system prompt, tool schemas, and any pasted context. Charged at the input rate ($10.00/1M for gpt-6-astra).

Cached input tokens

A repeated prompt prefix charged at 5% to 10% of the input rate ($0.10/1M for gpt-6.1-sol). Applies automatically when the same prefix recurs across calls.

Output tokens

The model's generated response. The most expensive component at 5x the input rate ($50.00/1M for gpt-6-astra). Trim output to control spend.

Processing Tiers: Batch, Flex, and Fast Mode

OpenAI sells the same models at five speeds. Batch runs asynchronous jobs at 50% of Standard. Flex bills the same 50% for latency-tolerant online traffic. Fast mode, renamed from Priority processing on July 30, 2026, costs 2x Standard. Ultrafast costs 6x Standard and is listed for gpt-6-astra and gpt-6.1-sol.

OpenAI processing tiers (gpt-6.1-sol, per 1M tokens, short context)
TierMultipliergpt-6.1-sol input/outputFits
Batch0.5x$1.00 / $5.00Async jobs, evals, backfills
Flex0.5x$1.00 / $5.00Latency-tolerant online traffic
Standard1x$2.00 / $10.00Default interactive traffic
Fast mode2x$4.00 / $20.00Latency-critical paths
Ultrafast6x$12.00 / $60.00Lowest-latency serving

On gpt-6-astra the same tiers run $5.00/$25.00 (Batch and Flex), $10.00/$50.00 (Standard), $20.00/$100.00 (Fast), and $60.00/$300.00 (Ultrafast). Regional processing (data residency) and FedRAMP endpoints add a 10% uplift for models released on or after March 5, 2026.

Long-Context Pricing

Every GPT-6 row carries two rates: a short-context rate and a higher long-context rate. Input and cached input double. Output rises 1.5x.

Short vs long context, Standard tier (per 1M tokens)
ModelInput (short / long)Cached input (short / long)Output (short / long)
gpt-6-astra$10.00 / $20.00$1.00 / $2.00$50.00 / $75.00
gpt-6.1-sol$2.00 / $4.00$0.10 / $0.20$10.00 / $15.00
gpt-6-luna$0.10 / $0.20$0.01 / $0.02$0.50 / $0.75
gpt-5.6-sol (Cyber)$4.00 / $8.00$0.40 / $0.80$20.00 / $30.00

Retrieval, compaction, and summarization that keep a request in the short-context band avoid the 2x input rate. For agents that re-send a long history every turn, that saving compounds across the session.

What Happened to GPT-4o and GPT-5 Pricing

OpenAI's flagship pricing tables now show only the GPT-6 family. The GPT-5.6 series moved: gpt-5.6-sol is listed under Cyber models at a promotional $4.00/$20.00, and gpt-5.6-terra and gpt-5.6-luna no longer appear in the main tables. GPT-4o survives in the audio section as gpt-4o-transcribe. Older chat models are in OpenAI's All models list, so check it before budgeting a legacy model.

Older and specialist rows still priced on OpenAI's page (per 1M tokens)
ModelInputCached inputOutput
gpt-5.6-sol (Cyber, promo)$4.00$0.40$20.00
gpt-5.6-cyber$12.50$1.25$75.00
gpt-5.3-codex$1.75$0.175$14.00
o4-mini (fine-tuned)$4.00$1.00$16.00
gpt-4o-transcribe$2.50n/a$10.00

For capability planning, gpt-6-astra replaces the GPT-5.6 flagship slot, gpt-6.1-sol covers general work, and gpt-6-luna covers high-volume classification and extraction at $0.10/1M input.

Cached Input Discount

Cached input is the largest discount OpenAI exposes directly in the price table. When the same prompt prefix repeats across calls, OpenAI bills the cached portion at a fraction of the input rate. gpt-6.1-sol has the deepest discount at 95%: $0.10/1M cached versus $2.00/1M uncached. The first write of a prefix bills at 1.25x the input rate.

Cached input vs standard input (per 1M tokens)
ModelStandard inputCached inputDiscount
gpt-6-astra$10.00$1.0090%
gpt-6.1-sol$2.00$0.1095%
gpt-6-luna$0.10$0.0190%
gpt-5.6-sol (Cyber)$4.00$0.4090%
gpt-5.3-codex$1.75$0.17590%

To capture the discount, put stable content first and variable content last. An agent that rebuilds its system prompt every turn, or interleaves changing context with fixed context, defeats the cache and pays the full input rate plus repeated cache writes.

Worked Example: A Coding Session

Take a coding session of 100 API calls totaling 300K input tokens and 100K output tokens, uncached, Standard tier.

100-call coding session (300K input, 100K output)
ModelInput costOutput costTotal
gpt-6-astra$3.00$5.00$8.00
gpt-5.3-codex$0.525$1.40$1.925
gpt-6.1-sol$0.60$1.00$1.60
gpt-6-luna$0.03$0.05$0.08

The all-flagship session costs $8.00. The all-luna session costs $0.08, a 100x difference. Neither extreme fits a real workload: luna misses the hard prompts, and gpt-6-astra is wasted on the easy ones. Split the same 100 calls by difficulty:

Routed session: same 100 calls, model matched to difficulty
DifficultyModelCallsCost
Easy (60%)gpt-6-luna60$0.048
Medium (25%)gpt-6.1-sol25$0.40
Hard (15%)gpt-6-astra15$1.20
Routed totalMixed100$1.648

The routed session costs $1.648 versus $8.00 all-flagship, a 79% reduction, with gpt-6-astra still on the hard 15%. Morph Router picks the model per prompt for $0.005 per request and returns the choice; your code makes the call.

$8.00
All gpt-6-astra, 100 calls
$1.648
Routed, 100 calls
79%
Saved by routing
100x
Astra vs luna per output token

Monthly Cost Scenarios

Monthly spend at Standard tier, uncached, assuming 1,000 input and 300 output tokens per request (light and medium) and 3,000 input and 1,000 output tokens per request (heavy agent traffic).

Monthly OpenAI API cost by volume (Standard tier)
Scenariogpt-6-astragpt-6.1-solgpt-6-luna
Light: 100 req/day (3M in, 0.9M out)$75.00$15.00$0.75
Medium: 1,000 req/day (30M in, 9M out)$750.00$150.00$7.50
Heavy: 10,000 req/day (900M in, 300M out)$24,000$4,800$240

Batch or Flex halves every figure for work that tolerates latency: the heavy gpt-6.1-sol month drops from $4,800 to $2,400. Cached prefixes cut the input share further.

ChatGPT Plus vs the API

ChatGPT Plus at $20/month and pay-per-token API access are different products. Plus covers the ChatGPT app and Codex. The API is billed separately per token no matter what you subscribe to.

At gpt-6.1-sol rates, a request of 1,000 input and 300 output tokens costs $0.005 ($0.002 input + $0.003 output). $20 buys 4,000 such requests, about 133 per day for a month. On gpt-6-luna the same request costs $0.00025, so $20 covers 80,000 requests. Heavy agent use on gpt-6-astra passes $20 in a few sessions.

Calling the API

The OpenAI API is OpenAI-SDK-compatible. You set the model string, send messages, and receive a response with a usage block that reports exact input and output token counts. Use that usage block to verify your cost estimates against real traffic instead of guessing.

OpenAI SDK call with usage accounting

import OpenAI from "openai";

const openai = new OpenAI();

const response = await openai.chat.completions.create({
  model: "gpt-6.1-sol",        // $2.00/1M input, $10.00/1M output
  messages: [
    { role: "system", content: "You are a coding assistant." },
    { role: "user", content: "Rename fetchUsers to loadUsers across the file." },
  ],
});

// The usage block reports exact token counts for cost accounting
const { prompt_tokens, completion_tokens } = response.usage;
const inputCost = (prompt_tokens / 1_000_000) * 2.00;
const outputCost = (completion_tokens / 1_000_000) * 10.00;
console.log("Call cost: $" + (inputCost + outputCost).toFixed(6));

Morph serves its own fast open-weight coding models, including DeepSeek V4.1 Flash and GLM-5.3, on an OpenAI-compatible API at https://api.morphllm.com/v1. Point the OpenAI SDK's baseURL at it to send easy prompts to a cheaper model without changing your code.

Same SDK, pointed at a Morph-served model

import OpenAI from "openai";

// Point the OpenAI SDK at Morph's OpenAI-compatible endpoint
const client = new OpenAI({
  apiKey: process.env.MORPH_API_KEY,
  baseURL: "https://api.morphllm.com/v1",
});

const response = await client.chat.completions.create({
  model: "morph-dsv41flash",  // DeepSeek V4.1 Flash served by Morph
  messages: [
    { role: "user", content: "Add a docstring to the parseConfig function." },
  ],
});
// Same usage block, same cost accounting as the OpenAI call above.

How to Reduce OpenAI API Costs

Four levers move OpenAI API spend, in order of impact. The first three are structural and apply within OpenAI; the fourth works across providers.

1. Route by difficulty

Send the easy 60% of prompts to gpt-6-luna at $0.50/1M output instead of gpt-6-astra at $50.00/1M, a 100x gap on those calls. Keep the flagship for the hard 15%.

2. Use cached input

Put the stable system prompt and tool schema first so the prefix caches at $0.10/1M instead of $2.00/1M on gpt-6.1-sol, a 95% discount on the repeated portion.

3. Batch what can wait

Evals, backfills, and nightly jobs run at a flat 50% discount on the Batch tier. Trim output tokens too: output costs 5x input on every GPT-6 model.

The router lever is the one most teams skip because it sounds like rebuilding their stack. It is not. A router classifies each prompt and returns the cheapest model that clears the quality bar, so the easy work stops hitting the flagship. Morph's router classifies in ~430ms (~$0.001 per classification) and routes across many models through one OpenAI-compatible endpoint at api.morphllm.com, cutting spend 40-70% without touching the rest of your code. See how the LLM router works and the cost calculator.

Same lever, every provider

The routing arithmetic is not OpenAI-specific. The same approach cuts spend on Anthropic and Google traffic, and a single router can span providers. Compare the Anthropic API pricing table to see the parallel structure: a flagship, a mid-tier at half the price, and a cheap small model for the bulk of the work.

Frequently Asked Questions

How much does the OpenAI API cost?

OpenAI bills per token. As of October 15, 2026, the flagship gpt-6-astra costs $10.00 per million input tokens, $1.00 per million cached input tokens, and $50.00 per million output tokens. gpt-6.1-sol costs $2.00/$0.10/$10.00 and gpt-6-luna costs $0.10/$0.01/$0.50. Batch and Flex bill at 50% of those rates, Fast mode at 2x.

How much does the GPT-6 API cost?

The GPT-6 family has three models. gpt-6-astra (flagship): $10.00/1M input, $1.00/1M cached input, $12.50/1M cache writes, $50.00/1M output. gpt-6.1-sol (mid-tier): $2.00 input, $0.10 cached, $2.50 cache writes, $10.00 output. gpt-6-luna (budget): $0.10 input, $0.01 cached, $0.125 cache writes, $0.50 output. Rates are Standard tier, short context.

What happened to GPT-5.6, GPT-5.5, GPT-5.4, and GPT-4o pricing?

OpenAI's flagship pricing tables now list only the GPT-6 family. gpt-5.6-sol appears under Cyber models at a promotional $4.00/1M input and $20.00/1M output, available at least through November 21, 2026, and gpt-5.3-codex is listed at $1.75/$0.175/$14.00. Older rows sit in the All models list on OpenAI's pricing page.

How does OpenAI cached input pricing work?

When the same prompt prefix repeats across API calls (a fixed system prompt, a tool schema, a constant document), OpenAI charges the cached portion at a reduced rate: $1.00/1M on gpt-6-astra (10% of input), $0.10/1M on gpt-6.1-sol (5%), and $0.01/1M on gpt-6-luna (10%). Writing a prefix to the cache bills at 1.25x the input rate.

How much does the OpenAI Batch API cost?

Batch runs requests asynchronously at 50% of Standard on input, cached input, cache writes, and output. gpt-6-astra drops from $10.00/$50.00 to $5.00/$25.00 per million tokens, gpt-6.1-sol to $1.00/$5.00, and gpt-6-luna to $0.05/$0.25. Flex bills the same rates for latency-tolerant online traffic.

What is OpenAI Fast mode pricing?

Fast mode is OpenAI's low-latency tier at 2x the Standard rate: gpt-6-astra costs $20.00/1M input and $100.00/1M output, gpt-6.1-sol $4.00/$20.00, gpt-6-luna $0.20/$1.00. Priority processing was renamed Fast mode on July 30, 2026. Ultrafast bills 6x Standard on gpt-6-astra and gpt-6.1-sol.

How does OpenAI long-context pricing work?

Each GPT-6 row carries a second, higher long-context rate. gpt-6-astra goes from $10.00/$50.00 to $20.00/$75.00 per million input/output tokens, gpt-6.1-sol from $2.00/$10.00 to $4.00/$15.00, and gpt-6-luna from $0.10/$0.50 to $0.20/$0.75.

Is ChatGPT Plus cheaper than the OpenAI API?

They are separate products: ChatGPT Plus ($20/month) covers the ChatGPT app and Codex, and API usage is always billed separately per token. At gpt-6.1-sol rates, $20 buys 2 million output tokens or 10 million uncached input tokens of API usage.

What is the cheapest OpenAI API model?

gpt-6-luna is the cheapest model in OpenAI's flagship table at $0.10/1M input, $0.01/1M cached input, and $0.50/1M output, or $0.05/$0.25 on Batch. It is 100x cheaper per output token than gpt-6-astra.

How do I reduce OpenAI API costs?

Four levers, in order of impact. Route easy prompts to cheaper models: gpt-6-luna at $0.50/1M output handles boilerplate that gpt-6-astra bills at $50.00/1M. Keep prompt prefixes stable so they hit the cache. Send offline work through Batch or Flex at 50% off. Trim output with tight max-token limits, since output costs 5x input.

Do input and output tokens cost the same on OpenAI?

No. Output costs 5x input on all three GPT-6 models. gpt-6-astra is $10.00/1M input and $50.00/1M output, gpt-6.1-sol is $2.00/$10.00, and gpt-6-luna is $0.10/$0.50.

Sources

Related Resources

Stop Paying Flagship Prices for Easy Prompts

Morph's router classifies each prompt in ~430ms and routes it to the cheapest model that clears the bar, across providers through one OpenAI-compatible endpoint at api.morphllm.com. 40-70% lower API spend, no code rewrite. Point the OpenAI SDK's baseURL at Morph and ship.