In this post I would to introduce you to a new one-page web app I built: Prompt Stash.
If you work in Data Science, Software Engineering or a related field, or even if you are just passionate about AI, chances are that you are working with multiple LLMs. Each one serves its purpose, but juggling them means your prompts are scattered everywhere, lost across countless tabs and infinite chat threads.
Prompt Stash is my attempt to fix that.
The Problem
Between work and personal projects, I found myself constantly switching between AI tools. And every time, I’d end up rewriting the same prompts from scratch, trying to remember what had worked before. It felt inefficient—especially when I knew some of these prompts were worth reusing, if only I had saved them somewhere.
I needed a place to save my prompts, organise them, and revisit them later. Something fast and simple to use.
The Solution
I’m a big fan of single-purpose, one-page apps — tiny tools that solve a single problem well (if you are curious I made another one called JupyterView). Prompt Stash follows that philosophy: it’s a fully self-contained HTML page built with HTML5, CSS3, and vanilla JavaScript. No frameworks, no backend, no nonsense.
It loads instantly, works offline, and is easy to extend and quick to debug.
Without further ado, let me show you around.
Prompt Stash UI
A clean interface with fields to enter a title, write your prompt, assign tags, and group them into projects.
The Prompt Stash UI
Current Features
This is still a work-in-progress, but I want that to be out in the world to gather some feedback and be inspired regarding future useful features.
Here’s what Prompt Stash can already do:
📁 Projects
Group your prompts into Projects — great if you’re using multiple LLMs on the same task. For example, keep all prompts related to a specific codebase in one project, so they’re always easy to find.
You can create new projects from the sidebar and assign prompts to them as you go, as shown in the two screenshots below.
create a new project using the sidebar
You can then assign a project when saving a prompt
🏷️ Tags
Add as many comma-separated tags as you like to any prompt. Tags help you track recurring themes across projects and make searching easier.
You can add comma-separated tags to your prompts
📝 Markdown Support
Prompt Stash supports basic Markdown! You can toggle between the raw Markdown view and a rendered preview. It’s a small touch, but it helps when formatting longer prompts.
A prompt written in markdown in its raw format
The same prompt with its markdown rendered
🔒 Local Storage Only
Your data is yours. Prompt Stash doesn’t upload anything — it uses your browser’s local storage only. That means no account required, no server involved… but also: don’t clear your cookies unless you’ve backed things up.
I know that’s a limitation, and I’m already planning improvements (see the roadmap below).
A perpetual beta
Prompt Stash proudly carries that Web 2.0 “Beta” spirit. It works, but it’s growing. I want to evolve it with feedback and turn it into a genuinely helpful tool for anyone crafting prompts regularly.
It’s Open Source
Prompt Stash is part of my one-page web apps collection. You can find the source code here:
👉 GitHub – feddernico/onepage-webapps
GitHub - feddernico/onepage-webapps: One page webapps created using only HTML5, CSS and Javascript
One page webapps created using only HTML5, CSS and Javascript - feddernico/onepage-webapps
If you’ve got ideas, spot bugs, or want to contribute, please open an issue on GitHub. I’d love to hear from you.
Roadmap
A few key features I’m working on:
Export & Import: Save all your prompts as a file, and re-import them later to avoid data loss.
Google Sync: Login with your Google account to sync prompts to a Google Sheet for easy backup and cross-device access.
Let Me Know What You Think
Prompt Stash is still in its early days, but I hope it’s already useful. If you try it out, I’d love your feedback—features you’d want, use cases you’ve discovered, or pain points you’ve hit.
Drop me a message, open an issue, or just fork the repo and build your own version.
Happy prompting!