Turn rough prompts into reusable, tested workflows.
Prompt Lab gives you one focused place to shape a draft, keep the version that works, and compare results when the work needs proof.
Start where you already work.
Web app
Open the complete workspace in a browser. No installation required.
Start free → Browser extension — setupExtension
Keep the workbench beside ChatGPT, Claude, and other browser-based AI tools.
View setup guide → Source buildDesktop
Keep a local build nearby for provider workflows and a focused desktop surface.
View source and build notes → No packaged installer is advertised.See exactly what changes.
This transparent sample uses fixed example content. It never reads or sends your text.
Shape it. Save it. Prove it.
One repeatable loop keeps prompt work from disappearing into chat history: improve the instruction, save the useful version, and compare outcomes when quality matters.
Sharpen drafts without losing the point
Use the workbench to turn rough instructions into usable prompts with fast iteration, quality checks, and enhancement modes that keep the original intent intact.
- Seven enhancement modes inside one working surface
- Prompt scoring and lint checks surface weak spots early
- One-click accept, copy, or iterate further
Keep and import the prompts worth reusing
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.
- Import preset packs, library exports, and starter bundles
- Full-text search across your entire library
- Compose longer prompts from saved fragments
Review runs instead of guessing
Keep evaluation history visible, compare variants when the workflow needs proof, and preserve the model context behind every result you reuse.
- Run timeline with provider, model, latency, and status
- A/B Compare and side-by-side diff available in Pro
- Extension and desktop support Claude, OpenAI, Gemini, OpenRouter, and Ollama
Built for the rest
of the workflow.
Your prompt library stays useful outside Prompt Lab.
The editor keeps prompts and libraries in local browser storage. Provider calls happen only when you choose to connect and run one.
Read the privacy policy →- Local by defaultDrafts and saved library items remain in this browser unless you export or connect another service.
- Provider choiceUse supported provider connections when a workflow needs a real model response.
- Exportable workKeep reusable prompts portable with the available library import and export tools.
Start free. Upgrade when useful.
The editor is free to use. Pro unlocks the comparison and organization tools that matter when prompt work becomes a repeatable practice.
- All 7 enhancement modes
- Prompt library with search
- Preset pack and library import
- Composer for saved prompt blocks
- Extension setup guide
- Local browser storage
- Everything in Free
- A/B Compare in Evaluate
- Side-by-side diff viewer
- Batch test-case runs
- Collections for grouped libraries
- JSON library export
Opens Prompt Lab and asks you to confirm before checkout. Selecting a plan here never charges you.
Know what happens before you open the app.
Do I need an account?
The hosted web app currently asks you to sign in. This landing-page sample does not, and it never sends example content to a provider.
Are AI provider costs included in Pro?
No. Provider usage is separate from Prompt Lab Pro and remains subject to the provider account or local model you choose.
Where are my prompts stored?
The web editor keeps prompts and libraries in local browser storage. A provider receives content only when you intentionally connect it and run a provider-backed action.
Where are provider API keys stored?
Configured keys stay in browser or extension storage. Hosted web requests pass through Prompt Lab's domain-allowlisted proxy for browser compatibility, but the keys are not persisted server-side.
How do I cancel Pro?
Use Manage Billing in Prompt Lab to open Stripe's customer portal, where you can manage or cancel the subscription.
Will choosing Pro charge me immediately?
No. The pricing choice opens Prompt Lab with your monthly or annual preference. You still review and confirm the billing flow inside the app.
Is there a desktop installer?
The repository includes desktop source and build notes. This page does not claim a packaged installer; use the web app unless you specifically want to build the desktop surface.
Build a prompt workflow,
not a prompt pile.
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.
Try PromptLab free