ChatGPT Balanced Verified 19 Aug 2026

GPT-5.5 Instant

The previous default ChatGPT model — fast, dependable, broadly capable.

Previous generation. Use GPT-5.6 Terra instead. Previous generation. GPT-5.6 shipped 9 Jul 2026.

Maker: OpenAI
Context: Large (see OpenAI docs)
Pricing: See OpenAI pricing / See OpenAI pricing

Best for

Everyday drafting, rewriting, brainstorming
Quick answers where latency matters
Accounts that haven't been moved to 5.6 yet

Prompting quirks

Use the system / custom-instructions slot

Persistent context (your role, your product, your tone) belongs in custom instructions, not re-pasted every prompt. Saves tokens and keeps outputs consistent.

Front-load the constraint

Put the format and length limit in the first sentence. Instant is eager to be helpful and will over-produce if you let it.

Copy-paste example

Tuned for GPT-5.5 Instant. Swap in your own content where marked.

Draft a release note

Write a release note for this change. Audience: existing customers.
Tone: clear, no hype. Max 80 words. Lead with the user benefit.
Change: {describe the change}

Facts verified against the official OpenAI docs on 19 August 2026.