Better for complex and multi-step tasks.
Release references (3)
Automatic switching from Instant to Thinking was retired for Plus and Pro users, while manual reasoning choices remain available
2026-09-14
Automatic switching from Instant to Thinking was retired for Plus and Pro users globally, and the Higher intelligence web setting was removed. Users can still choose an available reasoning option manually; safety-related switching may still occur.
Users now need to select a reasoning option when a complex task needs more thinking time instead of relying on automatic switching.
Availability at release: ChatGPT Plus and Pro users globally.
SourceThinking context expanded to 256k total
2026-02-20
Thinking mode context expanded to 256k total (128k input plus 128k max output).
Better handling of long prompts, long documents, and multi-step tasks.
Availability at release: Thinking mode users
SourceOriginal record fields
Source: https://help.openai.com/en/articles/6825453-chat-gpt-release-notes
date:Date:start: 2026-02-20
date:Date:end: null
date:Date:is_datetime: 0
Who Gets It: Thinking mode users
Category: Core Chat Experience
Why It Matters: Better handling of long prompts, long documents, and multi-step tasks.
What Changed: Thinking mode context expanded to 256k total (128k input plus 128k max output).
Student Facing: __NO__
Lifecycle: Active
Update: Thinking context expanded to 256k total
Thinking time toggle in composer
2025-09-17
Users can choose how long GPT-5 Thinking reasons before replying (faster vs deeper).
Gives control over speed-quality tradeoff depending on task type.
Availability at release: Plus, Business, Pro
SourceOriginal record fields
Source: https://help.openai.com/en/articles/6825453-chat-gpt-release-notes
date:Date:start: 2025-09-17
date:Date:end: null
date:Date:is_datetime: 0
Who Gets It: Plus, Business, Pro
Category: Core Chat Experience
Why It Matters: Gives control over speed-quality tradeoff depending on task type.
What Changed: Users can choose how long GPT-5 Thinking reasons before replying (faster vs deeper).
Student Facing: __NO__
Lifecycle: Active
Update: Thinking time toggle in composer