Draft, import, save, compose, and evaluate prompts in one local-first system. Use the hosted app, load the extension, or keep a desktop build nearby when repeatable prompt work matters.
Prompt Lab is built around one repeatable loop: shape the prompt, keep the version that works, and test the result when you need proof.
Use the workbench to turn rough instructions into usable prompts with fast iteration, quality checks, and enhancement modes that keep the original intent intact.
Keep evaluation history visible, compare variants when the workflow needs proof, and preserve the model context behind every result you reuse.
Save the prompts that earn a second life. Import Prompt Lab exports, starter libraries, or raw prompt arrays, then search and reuse the strongest blocks later.
Paste a rough prompt and watch Prompt Lab turn it into a cleaner, more reusable version.
No credit card required for the editor. Prompts and libraries stay in local browser storage unless you choose to call a provider or sync billing.
Open Prompt Lab on the web, install the extension when you want it beside the page, and keep a library that can move with you.
Open PromptLab