GPT-IN is an open-source Chrome extension that replaces ChatGPT’s plain-text input with a rich text editor featuring headings, formatted lists, tables, code blocks, and manual box resizing while preserving DOM state after sending.
Started in April 2025 to solve the pain of drafting long, structured prompts and questionnaires in the default web UI. Kept in a private refactoring loop for months until native formatting landed in ChatGPT.
Releasing the full codebase, historical GPT-4o UI screenshots, and demo video so the DOM extension architecture isn’t wasted.
- Repo :
github.com/aymen-cherife/gpt-in
-- Lesson learned.
