LOW-COST FRONTIERGPT-5.6 FAMILY1.05M CONTEXTTEXT + VISIONPROMPT CACHING
GPT-5.6 Luna API Pricing
GPT-5.6 Luna is OpenAI's lowest-price GPT-5.6 tier for cost-sensitive agents and production routing: $1/M input, $6/M output, and $0.10/M cached input. Generally available since July 9, 2026 across ChatGPT, Codex, and the API. Pulled directly from developers.openai.com daily.
Input - per 1M tokens
$1.00/M
Short context up to 272K input standard
Output - per 1M tokens
$6.00/M
Long context output is $4.50/M standard
Cached input - 90% off
$0.10/M
Prompt cache read price -90%
Effective - agentic blend
$0.72/M
92/8 split - 82% cache
§ 01 / TERMINAL
Run the numbers.
Live calculator pre-loaded with current GPT-5.6 Luna standard short-context rates. Tweak spend, output mix, or cache hit rate; share the URL to share the calculation.
$ /mo
Workload split
Prompt cache hit rate
Tokens you can process
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Words equivalent (English)
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Effective rate
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§ 02 / SCENARIOS
Real-world presets.
RAG - SUPPORT
Support agent ticket triage
$0.012/ticket
CLASSIFICATION
Bulk routing decision
$0.002/decision
CONTENT
SEO draft outline
$0.009/outline
ASSISTANT
Daily workflow turn
$0.004/turn
§ 03 / TOKENIZER
Paste text. See tokens. See cost.
Exact · o200k_base Auto-counts as you type
Counted with the o200k_base BPE encoding — the same tokenizer the API uses — entirely in your browser. The encoder loads on your first keystroke (~1 MB, one time); your text never leaves this page.
Characters 611
Words 95
Tokens (exact) 158 tokens
Cost as input · uncached $0.000158 USD
Cost as output · uncached $0.000948 USD
Cost as cached input $0.000016 USD
| Model | Input /M | Output /M | Effective blended | Context | Best for |
|---|---|---|---|---|---|
| GPT-5.6 Sol | $5.00 cache $0.50 | $30.00 | $3.61 same blend | 1.05M | Highest-accuracy GPT-5.6 preview |
| GPT-5.6 Terra | $2.50 cache $0.25 | $15.00 | $1.80 same blend | 1.05M | Balanced GPT-5.6 preview agents |
| GPT-5.6 Luna Current | $1.00 cache $0.10 | $6.00 | $0.72 agentic 92/8 | 1.05M | Cheapest GPT-5.6 preview routing |
| GPT-5.5 | $5.00 cache $0.50 | $30.00 | $3.61 same blend | 1M | Current broadly available OpenAI flagship |
| GPT-5.4 | $2.50 cache $0.25 | $15.00 | $1.80 same blend | 1.05M | Broadly available balanced OpenAI tier |
| GPT-5.4 mini | $0.75 cache $0.07 | $4.50 | $0.54 same blend | 400K | Lower-cost OpenAI subagents |
| Claude Opus 4.8 | $5.00 cache $0.50 | $25.00 | $3.21 same blend | 1M | Anthropic Opus frontier alternative |
| Gemini 3.5 Flash | $1.50 cache $0.15 | $9.00 | $1.08 same blend | 2M | Google multimodal context alternative |
Compare siblings
Frequently asked.
Practical GPT-5.6 Luna pricing questions, with OpenAI's published rates separated from workload assumptions.
Q · 01 How much does GPT-5.6 Luna cost? +
OpenAI lists GPT-5.6 Luna at
$1/M input tokens, $0.10/M cached input tokens, and $6/M output tokens in the standard short-context tier. Verified on OpenAI's pricing docs 2026-07-10.Q · 02 Is GPT-5.6 Luna generally available? +
Yes. OpenAI made the GPT-5.6 series (Sol, Terra, Luna) generally available on July 9, 2026 across ChatGPT, Codex, and the API, after an initial limited preview that opened June 26, 2026.
Q · 03 What is the context window? +
OpenAI's model docs list a
1.05M-token context window and 128K max output for GPT-5.6 Luna, with a stated knowledge cutoff of February 16, 2026.Q · 04 How much cheaper are Batch and Flex? +
OpenAI lists Batch and Flex for GPT-5.6 Luna at half the standard short-context rate:
$0.50/M input, $0.05/M cached input, and $3/M output. Priority is $2/M input, $0.20/M cached input, and $12/M output.Q · 05 When does long-context pricing apply? +
For requests above
272K input tokens, GPT-5.6 Luna uses the long-context tier: $1/M input, $0.10/M cached input, and $4.50/M output. The calculator on this page uses the standard short-context tier.Q · 06 Which GPT-5.6 tier should I choose? +
Use Sol for the hardest tasks, Terra for balanced agent workloads, and Luna for lower-cost routing or high-volume production. In the shared 92/8 agentic blend with 82% cache hits, Sol lands near
$3.61/M, Terra near $1.80/M, and Luna near $0.72/M.