Prompt engineering workbench
Stop juggling prompts in notepads.
Build them like code.
PromptLab is the workbench for teams that take prompts seriously. Version, test against any model, refine with AI, and share with your community.
Free foreverBring your own API keysNo credit card
promptlab.app/library
Prompt Library
🔍 Search prompts...⌘K
Code Review Agent
Thorough code reviewer that checks for bugs, security issues, and suggests improvements with examples.
v7Persona
Blog Post Generator
Creates SEO-optimized blog posts with proper headings, meta descriptions, and engaging intros.
v12Format
Data Analyst
Analyzes datasets, generates insights, and creates visualizations from raw CSV or JSON input.
v4Variable
Email Copywriter
Writes conversion-focused email sequences for product launches, onboarding, and re-engagement.
v9Persona
API Docs Writer
Generates comprehensive API documentation from endpoint definitions with request and response examples.
v3Format
UX Research Synthesizer
Processes interview transcripts into actionable insights with themed findings and recommendations.
v6Persona
Everything you need
From a rough idea to a shipped, versioned prompt — all in one tool.
🔖
Git for prompts
Every save creates a version. Compare changes, roll back to any point, and track how your prompt evolved from first draft to production.
v7 — Added few-shot examples2 hours ago
v6 — Tightened output formatyesterday
v5 — Switched to chain-of-thought3 days ago
v4 — Initial working versionlast week
✨
AI builder
Describe what you need in plain language. The AI generates a structured prompt with variables, constraints, and output formats built in.
📁
Reusable snippets
Build a library of persona blocks, format templates, and context chunks. Attach them to any prompt with a click.
Senior EngineerJSON Output{company_name}Max 500 words
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Test against any model
Run your prompt against Claude, GPT, Gemini, or any model. Compare outputs side by side and iterate until the results are exactly right.
🌎
Community gallery
Browse prompts shared by the community. Upvote the best ones, fork them into your library, and build on what others have started.
SQL Query Optimizer
by @elena
♥ 89 · 14 forks
Product Spec Writer
by @marcus
♥ 156 · 31 forks
Interview Prep Coach
by @priya
♥ 203 · 47 forks
🔑
Bring your own keys
Connect your API keys from any provider. We never charge you for AI usage and your keys stay encrypted at rest.
AnthropicOpenAIGoogleVercelOpenRouter
From idea to prompt in three steps
No setup, no configuration. Just describe, refine, and ship.
01
Describe your goal
Tell the AI what you need
Open the builder, describe your use case in plain language, and let the AI generate a structured prompt complete with variables, personas, and output constraints.
02
Refine and test
Iterate until it's perfect
Run your prompt against any model using your own API keys. Switch between Claude, GPT, and Gemini to compare outputs. Refine with AI assistance or edit manually.
03
Save, version, share
Ship with confidence
Every save is a version you can roll back to. When you're ready, publish to the community gallery. Others can fork and build on your work.
Loved by prompt builders
Teams use PromptLab to go from scattered notes to production-ready prompts.
“I used to have 40 different prompt files scattered across Notion, Google Docs, and random text files. PromptLab replaced all of that. The versioning alone saved me from losing my best iteration of our support agent prompt.
SC
Sarah Chen
Product Engineer at Raycast
“The test mode is a game-changer. Running the same prompt against Claude and GPT-4 side by side showed us exactly which model handled our edge cases better. We shipped our chatbot prompt three days faster.
MK
Marcus Kim
Head of AI at Lattice
“Our content team was writing prompts in Slack messages. Now they use PromptLab's snippet system to share persona blocks across prompts. Quality went up across the board, and onboarding new writers takes half the time.
AP
Amara Patel
Content Lead at Notion
Ready to ship better prompts?
Free forever. Bring your own API keys. Get started in 30 seconds.
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