OpenAI · previous generation

GPT-5 API pricing

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OpenAI's previous generations, from GPT-5 (August 2025) to GPT-5.6 (July 2026). All remain available through the API.

GPT-5.6 Sol

Promo price until 21 NovPrevious

Input

$4.00

per 1M tokens

Output

$20.00

per 1M tokens

Cached input

$0.40

90% off input

Batch

50% off

for jobs that can wait

Context window

1.05M

tokens

Verified 27 Sep 2026OpenAI pricing

Previous generation. The current replacement is GPT-6 Astra at $10.00 / $50.00 per 1M tokens.

What it costs in practice

GPT-5.6 Sol at list prices, no batch discount.

What GPT-5.6 Sol costs for three workloads
1,000 chat replies1,500 tokens in and 300 out each	$12.00
Summarising 100 long reports20,000 tokens in and 800 out each	$9.60
A month of a coding agent400 tasks, 85% of input cached	$865

The coding-agent example assumes 85% of input is served from cache, typical for agents that resend the same context each step. Model your own workload

Details

API model IDgpt-5.6-sol

Released9 Jul 2026

Long promptsPrompts over 272K tokens: 2× input, 1.5× output

PromotionPromotional price, in place until at least 21 November 2026.

Arena text score1483 (25 Sep)

StatusPrevious generation, still available

Checked 27 Sep 2026 against OpenAI pricing .

Other GPT-5 versions

GPT-5.6 Sol is on a promotional $4 / $20 until at least 21 November 2026. OpenAI cut GPT-5.6 Terra and Luna prices on 30 July 2026.

Other GPT-5 models and prices per million tokens
Model	Input / 1M	Output / 1M	Cached input	Context	Released
GPT-5.5Previous	$5.00	$30.00	$0.50	1.05M	23 Apr 2026
GPT-5.6 TerraPrevious	$2.00	$12.00	$0.20	1.05M	9 Jul 2026
GPT-5.4Previous	$2.50	$15.00	$0.25	1.05M	5 Mar 2026
GPT-5.2Previous	$1.75	$14.00	$0.18	400K	11 Dec 2025
GPT-5.6 LunaPrevious	$0.20	$1.20	$0.020	1.05M	9 Jul 2026
GPT-5.4 miniPrevious	$0.75	$4.50	$0.075	—	Mar 2026
GPT-5.4 nanoPrevious	$0.20	$1.25	$0.020	—	Mar 2026
GPT-5 miniPrevious	$0.25	$2.00	$0.025	400K	7 Aug 2025
GPT-5 nanoPrevious	$0.050	$0.40	$0.005	400K	7 Aug 2025

Version details

GPT-5.5

$5.00 / $30.00 per 1M tokenscached $0.50 · batch 50% off · 1.05M context

Released 23 Apr 2026 · gpt-5.5 · Prompts over 272K tokens: 2× input, 1.5× output

GPT-5.5 Pro costs $30 / $180 per 1M tokens.

Newer option: GPT-6 Astra at $10.00 / $50.00. Checked 27 Sep 2026 against OpenAI pricing and Fortune, 23 Apr 2026 .

GPT-5.6 Terra

▼ 20% on 30 JulPrevious

$2.00 / $12.00 per 1M tokenscached $0.20 · batch 50% off · 1.05M context

Released 9 Jul 2026 · gpt-5.6-terra · Prompts over 272K tokens: 2× input, 1.5× output

Newer option: GPT-6 Sol at $2.00 / $10.00. Checked 27 Sep 2026 against OpenAI pricing and Axios, 30 Jul 2026 .

GPT-5.4

$2.50 / $15.00 per 1M tokenscached $0.25 · batch 50% off · 1.05M context

Released 5 Mar 2026 · gpt-5.4 · Prompts over 272K tokens: 2× input, 1.5× output

Newer option: GPT-6 Sol at $2.00 / $10.00. Checked 27 Sep 2026 against OpenAI pricing .

GPT-5.2

$1.75 / $14.00 per 1M tokenscached $0.18 · batch 50% off · 400K context

Released 11 Dec 2025 · gpt-5.2

Newer option: GPT-6 Sol at $2.00 / $10.00. Checked 27 Sep 2026 against OpenAI pricing .

GPT-5.6 Luna

▼ 80% on 30 JulPrevious

$0.20 / $1.20 per 1M tokenscached $0.020 · batch 50% off · 1.05M context

Released 9 Jul 2026 · gpt-5.6-luna · Prompts over 272K tokens: 2× input, 1.5× output

Newer option: GPT-6 Luna at $0.10 / $0.50. Checked 27 Sep 2026 against OpenAI pricing and Axios, 30 Jul 2026 .

GPT-5.4 mini

$0.75 / $4.50 per 1M tokenscached $0.075 · batch 50% off

Released Mar 2026 · gpt-5.4-mini

Newer option: GPT-6 Luna at $0.10 / $0.50. Checked 27 Sep 2026 against OpenAI pricing .

GPT-5.4 nano

$0.20 / $1.25 per 1M tokenscached $0.020 · batch 50% off

Released Mar 2026 · gpt-5.4-nano

Newer option: GPT-6 Luna at $0.10 / $0.50. Checked 27 Sep 2026 against OpenAI pricing .

GPT-5 mini

$0.25 / $2.00 per 1M tokenscached $0.025 · batch 50% off · 400K context

Released 7 Aug 2025 · gpt-5-mini

Newer option: GPT-6 Luna at $0.10 / $0.50. Checked 13 Jun 2026 against OpenAI pricing .

GPT-5 nano

$0.050 / $0.40 per 1M tokenscached $0.005 · batch 50% off · 400K context

Released 7 Aug 2025 · gpt-5-nano

Newer option: GPT-6 Luna at $0.10 / $0.50. Checked 13 Jun 2026 against OpenAI pricing .

Compare GPT-5.6 Sol

No ready-made comparisons for this family yet.

Compare with any model

Price history

All changes

30 Jul 2026▼ 20%OpenAI cut GPT-5.6 Terra to $2 / $12 (from $2.50 / $15) and GPT-5.6 Luna to $0.20 / $1.20 (from $1 / $6). Source
9 Jul 2026OpenAI launched GPT-5.6 Sol ($4 / $20 promotional), Terra ($2.50 / $15) and Luna ($1 / $6). Source
23 Apr 2026OpenAI launched GPT-5.5 at $5 / $30. Source
5 Mar 2026OpenAI launched GPT-5.4 at $2.50 / $15. Source

Coming up

21 Nov 2026GPT-5.6 Sol's promotional $4 / $20 price is guaranteed until at least this date. Source

OpenAI pricing rules

Batch and Flex processing cost 50% less.
For GPT-5.4 and later, prompts longer than 272K tokens are billed at 2× the input price and 1.5× the output price.
Cached input is billed at about a tenth of the input price.

All OpenAI models

Questions

How much does GPT-5.6 Sol cost?

As of 27 Sep 2026, GPT-5.6 Sol costs $4 per million input tokens and $20 per million output tokens, and $0.40 per million cached input tokens. Batch requests cost 50% less. Prices checked 27 Sep 2026.

What is the cheapest GPT-5 model?

GPT-5 nano, at $0.05 / $0.40 per million input / output tokens.

What is GPT-5.6 Sol's context window?

1.05M tokens.

Does GPT-5.6 Sol support prompt caching?

Yes. Repeated input read from the cache costs $0.40 per million tokens, 90% less than normal input.