# OpenAI cuts GPT-5.6 Luna price 80%, adds Fast mode for Sol

By Steven Van · 2026-07-29

Terra drops 20% too, and Auto-review now runs on Luna at roughly a tenth of the previous cost.

OpenAI announced a round of price and speed changes across its GPT-5.6 lineup, framed as a direct commitment to the price-performance frontier: cost efficiency, capability, and speed all moving in the same direction at once. GPT-5.6 **Luna** drops 80% in price, GPT-5.6 **Terra** drops 20%, and GPT-5.6 **Sol** gets a new Fast mode in the API.

## Where the savings show up

The lower Luna and Terra prices aren't limited to raw API calls, they're reflected in how usage is counted in [Codex](<https://creatorstoolbox.com/tools/openai-codex>) and ChatGPT Work, so the same subscription or usage allocation goes further without any change on the user's end. OpenAI also upgraded **Auto-review** in the ChatGPT app and Codex CLI from GPT-5.4 to GPT-5.6 Luna. Combined with Luna's new pricing, OpenAI expects Auto-review to cost roughly 10x less to run, a meaningful shift for anyone leaning on automated code review as part of an agentic workflow.

## A faster option for Sol, at a cost

Alongside the price cuts, GPT-5.6 Sol gets a Fast mode in the API: up to 2.5x the speed of standard processing, at 2x the standard price, with no change in intelligence. That mirrors a pattern other labs have adopted recently, offering the same model at a latency-optimized tier for workloads where speed matters more than per-token cost, alongside the default tier for everything else.

## Why OpenAI frames this as efficiency, not just discounting

OpenAI's own explanation ties the price cuts to real efficiency gains made with the help of GPT-5.6 Sol itself, passing those gains back to developers rather than banking them as margin. The company has been shipping frequent model updates at a fast clip, and this release continues that cadence: rather than a single flagship jump, it's a tuning pass across the existing GPT-5.6 family that changes what the same budget buys.

## Ripple effects across the ecosystem

Platforms built on top of OpenAI's API models felt the change immediately. Unity AI assistant [Bezi](<https://creatorstoolbox.com/tools/bezi>) called the cut a big deal for its own users, since Luna and Terra's lower prices pass straight through to whatever OpenAI-powered features Bezi runs on top of them.

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Sources: [OpenAI](<https://openai.com/index/advancing-the-price-performance-frontier-with-gpt-5-6/>), [OpenAI on X](<https://x.com/OpenAI/status/2082878156483219672>).

[Read OpenAI cuts GPT-5.6 Luna price 80%, adds Fast mode for Sol on Creators Toolbox](<https://creatorstoolbox.com/blog/gpt-5-6-price-cuts-fast-mode-sol>)

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Canonical source: https://creatorstoolbox.com/blog/gpt-5-6-price-cuts-fast-mode-sol