PrefillPrompt

PrefillPrompt turns a prompt into a shareable link for ChatGPT, Claude, Gemini, or Perplexity. Choose an AI and model in one searchable field, write the prompt, then tap the arrow to copy the link.

[!IMPORTANT] The prompt is part of the URL. Anyone who receives the link—and systems that record URLs—can read it. Do not put secrets or sensitive personal information in a shared prompt.

Features

• ChatGPT, Claude, Gemini, and Perplexity destinations
• One provider-and-model combobox, searchable by names such as ChatGPT, OpenAI, Claude, Anthropic, Gemini, or an exact model
• Flexible aliases latest, latest-fast, and latest-reasoning
• A checked-in model catalog refreshed from OpenRouter through tested weekly pull requests
• ChatGPT web-search links
• Experimental temporary or incognito conversation links where the destination supports them
• Copyable URLs and Markdown buttons
• QR-code export and native Web Share where the browser supports it
• Progressively disclosed share formats, conversation options, examples, and browser-local history
• A reliable copy-and-open Gemini handoff when a public deep link cannot preserve the prompt
• A stateless Nuxt application deployed with Cloudflare Workers and Static Assets

History and preferences stay in the current browser. PrefillPrompt does not sync them between devices.

Privacy

PrefillPrompt has no account system, application database, analytics SDK, or advertising tracker. Preferences and up to six recent prompts are optional browser-local history. The app continues to work when browser storage is denied or full.

Prompt links are not private: the prompt is encoded in the URL and can appear in browser history, clipboards, QR scanners, link previews, network infrastructure, and destination-provider logs. Do not put secrets or sensitive information in a PrefillPrompt URL. See Privacy and logging for the exact storage, request, and logging behavior.

Try an example

Destination	Prompt	Link
ChatGPT with web search	Research the current state of Web Platform Baseline and cite primary sources.	Open prompt
Claude	Turn these rough release notes into a concise customer announcement.	Open prompt
Gemini	Compare three ways to add offline support to a Nuxt app, including tradeoffs.	Open prompt
Perplexity	Find primary sources explaining Cloudflare Workers Static Assets routing.	Open prompt

Prompt-link API

GET https://prefillprompt.com/api/prompt redirects the browser to the selected service with the prompt and supported options.

A link redirects straight to its service: the one it names, else the one its model implies, else ChatGPT. The one exception is a prompt that trips a safety signal. That link stops at a preview screen, /open, so the reader sees the warning before anything opens.

Query key	Required	Meaning
q	Yes	The URL-encoded prompt text. Newlines and Unicode are supported.
s	No	Service ID or recognized service alias. Supported IDs are chatgpt, claude, gemini, and perplexity. A provider-specific model may imply its service. With no service, the link opens ChatGPT.
m	No	Legacy name for the service. It is used only when s is absent. New links should use s.
model	No	A provider model ID or the alias latest, latest-fast, or latest-reasoning.
web	No	Set to true or 1 to request ChatGPT web search.
temporary	No	Set to true or 1 to request ChatGPT Temporary Chat or Claude Incognito. Experimental.

For example:

https://prefillprompt.com/api/prompt?s=chatgpt&model=latest-reasoning&web=true&q=Compare%20the%20latest%20browser%20automation%20standards

https://prefillprompt.com/api/prompt?s=chatgpt&temporary=true&q=Help%20me%20brainstorm%20three%20names%20for%20a%20weekend%20prototype

The preview screen

https://prefillprompt.com/open takes the same query keys as the API and never redirects on its own. It shows the prompt, any safety warning, and one frame of places to open it. Every place has its own Open link, so opening takes one click. Once a place is known, from the link or from a saved choice, the frame starts as a single button for it, and a toggle beside the button opens the rest of the list inside the same frame.

• Destinations. ChatGPT website, Claude website, Gemini, and Perplexity, plus two apps on computers: Codex in the ChatGPT desktop app (codex://new?prompt=) and Claude Code in a terminal (claude-cli://open?q=). Both app links are the vendors' documented forms; they fill the prompt in and wait for the reader to send it. If the app does not take over within a second and a half, the page offers the website. Touch devices are offered websites only, since a phone hands those links to an installed app itself.
• Remembered choice. For a link with no s, the destination the reader opens is saved in that browser and becomes the single button next time.
• A named service wins for one visit. With s=claude, the preview opens on Claude and leaves the saved choice alone. The saved choice still decides between app and website.

Link to /open?s=claude&q=… directly when you want the preview and the app option even for a clean prompt.

This is the beginning of the README. Read the rest at the original. Read the full README ↗