ChatGPT's Free Tier Just Got a Massive Upgrade: GPT-5.6 Luna Explained
OpenAI cut GPT-5.6 Luna's API price 80% on July 30, then made it the unlimited default model for ChatGPT's Free and Go tiers the following week. Here's what actually changed.
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On July 30, 2026, OpenAI cut GPT-5.6 Luna's API pricing by 80%, down to $0.20 per million input tokens and $1.20 per million output tokens. A week later, the change showed up somewhere a lot more people would notice: Luna became the default model for ChatGPT's Free and Go tiers, with unlimited text chats.
Before this, free users were capped on how many messages they could send per day and ran on GPT-5.5 by default. Now the cap is gone for text chats, and free users also get the "Think" reasoning toggle, a feature that used to sit further behind a paywall.
Why now
Cheaper serving costs are almost certainly the reason. An 80% price cut isn't a marketing gesture, it reflects OpenAI's actual cost to run Luna dropping enough that giving it away unlimited to free users stopped being a loss leader. GPT-5.6 Terra, the tier above Luna, got a price cut the same day: down 20% to $2 per million input tokens and $12 per million output. Terra also picked up an optional Fast mode, 2.5x faster at double the normal cost.
| Model | Change | New price (input / output per 1M tokens) |
|---|---|---|
| GPT-5.6 Luna | 80% cut, now free default | $0.20 / $1.20 |
| GPT-5.6 Terra | 20% cut, gained Fast mode | $2 / $12 |
What this means if you're on the free plan
If you were on ChatGPT free and hitting the daily message cap, that ceiling is gone for text chats. You're running on a genuinely capable model by default instead of getting routed to whatever the cheapest option was. The gap between free and paid ChatGPT just got narrower for anyone who mostly wants to talk to the model and doesn't need image generation, Sora access, or the largest context windows. For comparison, see how [GitHub Copilot's free tier](https://questloops.com/blog/github-copilot-pricing-2026-free-pro-pro-and-the-new-ai-credits-system) stacks up if coding is more your focus.
What this means if you're paying for Terra or building on the API
Terra got 20% cheaper and picked up Fast mode. If your workload is latency-sensitive, that 2.5x speed option at 2x cost is worth testing against your normal Terra calls, especially for anything customer-facing where response time affects completion rates. It's also a good moment to revisit pricing across the board. [Claude Sonnet 5's intro pricing](https://questloops.com/blog/claude-sonnet-5-s-intro-pricing-ends-august-31-what-the-50-jump-actually-costs-you) is ending the same month, and xAI just repriced [Grok 4.6](https://questloops.com/blog/grok-4-6-explained-pricing-benchmarks-and-what-changed) too, so August 2026 is turning into a genuine reshuffle across the major model providers.
The catch worth knowing about
An unlimited free tier sounds like a pure win, and mostly it is, but "unlimited" here means unlimited *text* chats specifically. It doesn't extend the same way to image generation, file uploads, or the heavier agent features, so free users will still hit walls outside plain conversation. Worth checking your account's actual limits before assuming everything opened up at once.
Quick answers
**Is GPT-5.6 Luna actually free now?** Yes, for text chats on the Free and Go tiers, with no daily message cap.
**When did this happen?** The pricing cut landed July 30, 2026; the free-tier rollout followed the week of August 6.
**Did paid plans get anything out of this?** GPT-5.6 Terra dropped 20% in price and gained an optional 2.5x-faster Fast mode at double the cost.
