ChatGPT's free tier is the most "asterisk-heavy" of the three major AI tools—the feature grid marks nearly everything as "limited." But look closer and there's a surprise: GPT-5.6 Terra is actually available on Free.
This article is built from OpenAI's official pricing page data (source): what ChatGPT Free can actually do, and what "limited" really means for each feature. Prices below are list prices as of 2026-08-12. Check the ChatGPT website for the latest rates.
Model access: GPT-5.5 Instant is the main workhorse; GPT-5.6 Terra hides behind specific doors
ChatGPT Free's standard chat runs on GPT-5.5 Instant with 27K context, but free users get limited GPT-5.6 Terra access through desktop Work and Codex—GPT-5.6 Sol and Luna require Go or above. Per ChatGPT's official pricing feature grid, here's the Free tier's actual model landscape:
| Model | Free Access? | Details |
|---|---|---|
| GPT-5.5 Instant | ✅ | Main chat model, 27K context, ~12 pages input |
| GPT-5.6 Terra | ✅ (limited) | Only via desktop ChatGPT Work and Codex |
| GPT-5.6 Sol | ❌ | Requires Go or above |
| GPT-5.6 Luna | ❌ | Requires Go or above |
| GPT-5 Thinking Mini | ❌ | Requires Go or above |
An important detail: the pricing page's top-level summary says "limited GPT-5.5 Instant access" without mentioning Terra—but scrolling to the feature grid, the Free column under GPT-5.6 Terra explicitly reads "Desktop Work and Codex (limited use)." This suggests Terra's Free availability is a recent adjustment not yet reflected in the summary copy.
GPT-5.6 Terra is a capable mid-tier model in the GPT-5.6 family, positioned for workspace and coding use. It handles code generation, bug fixes, and code review well. But the catch: it only works through desktop ChatGPT Work and Codex—the web chat uses GPT-5.5 Instant.
Feature openness: everything's here, everything's "limited"
ChatGPT Free's feature list looks broader than Claude Free's, but every item carries the 'limited' tag—OpenAI doesn't publish exact caps, dynamically adjusting based on server load and abuse prevention, making the actual experience inconsistent. ChatGPT Free's feature list looks broader than Claude Free's—but every item carries the "limited" tag (source):
| Feature | Free | Notes |
|---|---|---|
| Messages | ✅ | Limited |
| File uploads | ✅ | Limited |
| Image generation | ✅ | Limited, slower |
| Codex | ✅ | Limited use |
| ChatGPT Work | ✅ | Desktop app, limited use |
| Deep Research | ✅ | Limited use |
| Data analysis | ✅ | Limited |
| Vision | ✅ | Limited |
| Web search | ✅ | Available |
| Voice | ✅ | Limited |
| Memory | ✅ | Limited |
| GPTs/plugins | ✅ | Limited |
OpenAI doesn't publish exact numbers for "limited." Caps are dynamic, based on server load and abuse prevention. This means the experience fluctuates: on quiet hours you can go for a long stretch; during peak times you might get throttled after a few tasks.
The pricing page also explicitly marks Free as "bandwidth and availability constrained" (source). Paid users get priority during peak hours, and Free users will feel the slowdown.
The Go tier ($5/mo): what one step up unlocks
Go (~$5/mo) adds over Free: GPT-5.6 Luna and Thinking Mini access, higher message/upload limits, 54K Instant context (double Free's 27K), longer memory, and faster responses—but may include ads, and GPT-5.6 Sol still requires Plus. ChatGPT Go sits between Free and Plus at roughly $5/mo. Here's what it adds over Free (source):
- GPT-5.6 Luna and Thinking Mini: models Free can't touch
- Higher limits: messages, uploads, Codex, and Work all significantly expanded
- 54K Instant context: double Free's 27K
- Longer memory: including past-conversation memory
- Faster responses: no longer labeled "bandwidth constrained"
- Ads may appear: Go's page notes "This plan may include ads"—Free and Plus don't have this
GPT-5.6 Sol still requires Plus ($20/mo). Go is the mid-tier option for more models, more quota, and faster responses—but if you want the flagship model, Plus is the threshold.
How to use ChatGPT Free effectively
ChatGPT Free's strongest single move is GPT-5.6 Terra + Codex for coding—open the desktop ChatGPT Work, switch to Codex mode, and you're on GPT-5.6 Terra at zero cost—but all features being 'limited' means it's unreliable as a daily driver. ChatGPT Free's strongest single move is GPT-5.6 Terra + Codex for coding. If you primarily use ChatGPT for programming tasks, open the desktop ChatGPT Work, switch to Codex mode, and you're on GPT-5.6 Terra—arguably the best zero-cost coding experience among the three major tools.
Two things to keep in mind:
- Every feature is "limited," meaning unstable. Today's access doesn't guarantee tomorrow's, and peak-hour performance drops noticeably. It's not reliable as a daily driver.
- No GPT-5.6 Sol. Complex architecture design, extended reasoning, and multi-round agent workflows need Sol—and Free can't deliver. If your workflow frequently requires advanced reasoning, Free will fail at critical moments.
The key difference from Claude Free: ChatGPT gives you a "taste" of flagship capability (Terra) but layers "limited" over everything—continuity suffers. Claude Free holds back Opus, but what it gives you works consistently.