Did OpenAI Cut Prices? GPT-5.6 Sol, Terra, Luna
OpenAI cut GPT-5.6 API prices on July 30, 2026: Luna by 80 percent, Terra by 20 percent, Sol not at all. The cheap floor deleted in June is back.
By Capital & Compute
Ask this question in June and the answer was no. OpenAI previewed GPT-5.6 on June 26, 2026 with a restructured ladder (Sol, Terra, Luna) and no change to the headline rate, which set off two camps that could not both be right: one saying the models got more expensive, one saying OpenAI had shipped the cheapest frontier model on the market.
On July 30 OpenAI answered the question directly. In Advancing the price-performance frontier with GPT-5.6, it cut Luna by 80 percent and Terra by 20 percent, effective the same day, and left Sol alone. That is a real cut on published rates, five weeks after a launch that contained none. It also closes the specific hole the June launch opened.
Did OpenAI cut prices with GPT-5.6?
Yes, but not at launch and not at the top. The sequence matters:
- June 26, 2026 (launch): no headline cut. GPT-5.6 arrived as three tiers priced at $5 / $30 (Sol), $2.50 / $15 (Terra) and $1 / $6 (Luna). Sol held GPT-5.5’s rate exactly, and because there was no nano-class tier, the cheapest output token OpenAI sold inside the new family jumped from GPT-5.4 nano’s $1.25 to Luna’s $6.
- July 30, 2026 (the cut): Luna fell to $0.20 / $1.20 and Terra to $2 / $12. Sol was excluded. OpenAI attributed the reductions to inference efficiency gains found while building GPT-5.6, and said Terra and Luna now consume fewer credits inside ChatGPT Work and Codex, whose subscription prices did not change.
So the honest answer to the June version of this question was “no, it restructured the ladder.” The answer to the July version is “yes, and the cut landed almost entirely on the budget tier.”
The prices, against the menu they replace
| Model | Input / Mtok | Output / Mtok | Note |
|---|---|---|---|
| GPT-5.6 Sol | $5.00 | $30.00 | unchanged on July 30 |
| GPT-5.6 Terra | $2.00 | $12.00 | was $2.50 / $15, cut 20 percent |
| GPT-5.6 Luna | $0.20 | $1.20 | was $1.00 / $6.00, cut 80 percent |
| GPT-5.5 | $5.00 | $30.00 | prior flagship, same rate as Sol |
| GPT-5.4 mini | $0.75 | $4.50 | prior cheap tier |
| GPT-5.4 nano | $0.20 | $1.25 | prior floor, now beaten by Luna |
Current GPT-5.6 rates are from OpenAI’s own API pricing documentation, which also lists cached input at 90 percent off ($0.50, $0.20 and $0.02 respectively), Batch and Flex at 50 percent off standard, and Fast mode at exactly twice standard. The GPT-5.4 mini and nano rates come from model trackers such as PricePerToken, which list mini at $0.75 / $4.50 and nano at $0.20 / $1.25.
The ladder, remapped
Plot the pre-GPT-5.6 menu and today’s GPT-5.6 ladder on the same price axis and the July 30 cut shows up as the bottom rung sliding back into place. When this chart was first drawn in June, there was a shaded gap between $1.25 and $6 marking the price range GPT-5.6 no longer covered. That gap has closed: Luna at $1.20 now sits marginally below where GPT-5.4 nano sat.
| Ladder | Model | Output price per million tokens |
|---|---|---|
| Before 5.6 | GPT-5.4 nano | $1.25 |
| Before 5.6 | GPT-5.4 mini | $4.50 |
| Before 5.6 | GPT-5.5 | $30 |
| GPT-5.6 now | Luna | $1.20 |
| GPT-5.6 now | Terra | $12 |
| GPT-5.6 now | Sol | $30 |
Who actually saves, and by how much
Because every rate inside a tier moved by the same factor (Terra to 0.8x, Luna to 0.2x on input, output and cache read alike), cost per task scales by exactly that factor. There is no token-mix assumption to argue about.
Artificial Analysis measured the launch rates at about $1.04 per Intelligence Index task on Sol, $0.55 on Terra and $0.21 on Luna. Applying the cut, and noting that Artificial Analysis had not yet republished its own figures as of July 31, the same work now runs near $0.44 on Terra and roughly $0.042 on Luna. Sol stays at $1.04. That makes Luna about 25 times cheaper per task than Sol for a model four points behind Terra on the Intelligence Index.
The cheap floor came back
This is the part that reversed. At launch, the GPT-5.6 family contained nothing under $6 per million output tokens, and the two rungs OpenAI used to sell below that line, GPT-5.4 mini at $4.50 and nano at $1.25, had no successor. For the high-volume, low-reasoning jobs that are most of production AI (summarization, classification, tagging, extraction, routing) the new family offered Luna at $6 or nothing.
At $0.20 / $1.20, Luna is now cheaper than the nano it never replaced: identical on input, about 4 percent below it on output, and a considerably stronger model. The workloads that had no GPT-5.6 destination in June have one in July, and the argument for keeping traffic on GPT-5.4 nano has mostly evaporated. Non-OpenAI budget models are still worth costing against it, the same way Claude Haiku 4.5 stays a sane choice for well-scoped tasks, but the OpenAI-shaped hole in that comparison has closed.
The wider pattern still holds. The flagship rate has not moved since April 2026 while the bottom of the ladder fell 80 percent in a single announcement, which is the frontier-floor dynamic this site tracks in cost per token over time: capability at the edge stays sticky, and everything behind it collapses in price.
Terra is now the awkward tier
The cut was not evenly distributed, and that created a new problem. Terra fell 20 percent while Luna fell 80 percent, so the gap between them widened from about 2.5x to 10x on published rates. For that 10x you get two extra points of coding composite (77 against 75) and four of Intelligence Index (55 against 51).
Artificial Analysis had already noted before the cut that Sol and Luna sat ahead of Terra at every point on its intelligence-versus-cost curve, meaning Terra was already hard to justify: anything Terra could do, either Luna could do for less or Sol could do better. The July 30 cut made that worse, not better. If you standardised on Terra at launch, re-testing the same workload on Luna is now the single highest-value thing to do with an afternoon.
So should you switch?
- On cheap, high-volume work, switch and switch now. This is where the entire cut landed. Luna at $0.20 / $1.20 is the cheapest thing OpenAI has ever sold per output token, and it is a stronger model than the nano tier it undercuts.
- On mid-tier work, re-test Luna before you renew a Terra budget. Terra costs 10x Luna for a small capability delta. That delta is real on hard tasks and close to irrelevant on easy ones, so only your own evaluation settles it.
- On frontier-grade tasks, nothing changed. Sol is still GPT-5.5’s price. Budget exactly as before and let token efficiency decide whether the bill drifts.
The June version of this release was a price cut dressed as a price hold. The July version is the actual cut, and it is concentrated so heavily at the bottom of the ladder that the interesting question is no longer whether GPT-5.6 got cheaper, but whether its middle tier still has a reason to exist.
Frequently asked questions
- Did OpenAI cut prices with GPT-5.6?
- Yes, on July 30, 2026, though not at launch. OpenAI cut GPT-5.6 Luna by 80 percent to $0.20 input / $1.20 output per million tokens and Terra by 20 percent to $2 / $12. Sol was excluded and still costs $5 / $30, the same as GPT-5.5. At the June 26 launch there had been no headline cut at all, only a restructured ladder.
- How much did GPT-5.6 Luna and Terra prices drop?
- Luna fell 80 percent, from $1 input / $6 output per million tokens to $0.20 / $1.20. Terra fell 20 percent, from $2.50 / $15 to $2 / $12. Cached input fell by the same proportion on both, to $0.02 and $0.20. The changes took effect July 30, 2026 and also rolled out on Amazon Bedrock.
- Is there a GPT-5.6 nano model?
- No, GPT-5.6 still ships as three tiers with no nano-class option. But after the July 30 price cut the question matters much less: Luna at $0.20 input / $1.20 output now matches the retired GPT-5.4 nano on input and undercuts it on output, while being a stronger model. The cheap floor that disappeared at launch is effectively back.
- Is GPT-5.6 more expensive than GPT-5.4?
- No longer. At the June launch the cheapest GPT-5.6 model, Luna at $6 output, cost nearly five times GPT-5.4 nano at $1.25, so low-end workloads faced a large increase. The July 30 cut took Luna to $1.20 output, below the nano floor, so GPT-5.6 is now cheaper than GPT-5.4 at both the bottom and the middle of the ladder.
- Should I use GPT-5.6 Terra or Luna?
- Start with Luna. After the July 30 cut Terra costs about 10 times Luna per token while scoring two points higher on the coding composite and four on the Artificial Analysis Intelligence Index. Artificial Analysis had already found Sol and Luna ahead of Terra at every point on its intelligence-versus-cost curve, and the uneven cut widened that gap.
- What replaced Priority Processing in the OpenAI API?
- Fast mode. Announced alongside the July 30 price cut, it bills at exactly twice the standard rate for responses OpenAI says are up to 2.5x quicker on Sol, and it aligns with the /fast flag in Codex. API requests already tagged priority continue to work.
- Did the July 30 cut change ChatGPT or Codex subscription prices?
- No. OpenAI said ChatGPT and Codex subscription prices and quota budgets are unchanged. The practical effect for subscribers is indirect: Terra and Luna now consume fewer credits, so the same quota stretches across more tasks.
Sources
- OpenAI. (2026). Advancing the price-performance frontier with GPT-5.6 [vendor announcement; the July 30 2026 Terra and Luna price cuts, Sol held, Fast mode replacing Priority Processing, credit consumption]. Verified 2026-07-31. openai.com/index/advancing-the-price-performance-frontier-with-gpt-5-6
- OpenAI. (2026). API pricing [primary; current standard, cached, Batch, Flex and Fast mode rates for Sol, Terra and Luna]. Verified 2026-07-31. developers.openai.com/api/docs/pricing
- OpenAI. (2026). Previewing GPT-5.6 Sol: a next-generation model [vendor preview post; the June 26 launch ladder and positioning]. Verified 2026-06-27. openai.com/index/previewing-gpt-5-6-sol
- Amazon Web Services. (2026). Amazon Bedrock announces up to 80% lower prices for OpenAI GPT-5.6 models [provider announcement corroborating the 80 percent Luna and 20 percent Terra reductions, effective July 30 2026]. Verified 2026-07-31. aws.amazon.com
- CNBC. (2026). OpenAI cuts prices for two of its GPT-5.6 AI models as companies grow sensitive to costs [news; corroborates the pre-cut Terra $2.50 / $15 and Luna $1 / $6 rates]. Verified 2026-07-31. cnbc.com
- Artificial Analysis. (2026). GPT-5.6 Terra and GPT-5.6 Luna model pages [independent benchmark; Intelligence Index 55 and 51, and the launch-rate cost per index task of $0.55 and $0.21 that the post-cut figures are derived from]. Verified 2026-07-31. artificialanalysis.ai
- PricePerToken. (2026). GPT-5.4 nano and GPT-5.4 mini API pricing [secondary model tracker; nano $0.20 / $1.25, mini $0.75 / $4.50]. Verified 2026-06-27. pricepertoken.com