What is SimmerDown?
SimmerDown offers a modular, easy-to-use library of ChatGPT pre-prompts; pre-prompts are instructions placed at the start of a ChatGPT query that guide the model to generate more detailed and relevant responses. By streamlining the process of using pre-prompts and supporting quick command inputs, this extension helps users fully unlock ChatGPT’s potential.
Key features
It supports quick commands (such as !expert) that allow one-click insertion of complex pre-prompts, significantly saving time compared to manual typing; all pre-prompts and custom commands are stored locally, with no uploads or external sharing, ensuring user privacy and security.
Users can create and save their own custom commands tailored to different workflows and personalized needs; these pre-prompts cover a wide range of scenarios, including invoking expert knowledge, setting specific writing styles, and handling diverse content-generation tasks.
Use cases and audience
Ideal for everyday users, content creators, developers, and researchers who need efficient, customizable ways to utilize ChatGPT pre-prompts.
- Automatically inserts ChatGPT pre-prompts, enhancing the detail and relevance of responses.
- Quickly invoke complex pre-prompts with shorthand commands (e.g., !expert), saving time on manual input.
- Create and save custom pre-prompt commands tailored to personal or professional needs.
Users type shorthand commands (such as !expert) or custom commands into the ChatGPT input box.
These commands automatically expand into full pre-prompt text and are inserted at the beginning of the current ChatGPT input field.
Frequently asked questions
Does SimmerDown upload or transmit my pre-prompts or chat content?
No. All pre-prompts and commands are stored locally on the user’s device; there is no “phone home” data transmission, and no user data is sent to external servers.
Can I disable this extension when not in use?
Yes. The extension provides a one-click enable/disable toggle, allowing users to control the feature at any time.
How to use
- 01
Install the SimmerDown extension in the Chrome browser.
- 02
Open the ChatGPT website and ensure the extension icon is activated.
- 03
Type a shorthand command (e.g., !expert) into the ChatGPT input box; it will automatically expand into a full pre-prompt.
- 04
Enter follow-up questions, and ChatGPT will generate customized responses based on your pre-prompt.
Official website & sources
Updated on 2026-11-02

