Stop Guessing.Start EngineeringThe Perfect Prompts.
PromptLab helps creators, marketers, and developers instantly generate, test, and optimize prompts across top AI providers like OpenAI, Anthropic, Google, and more. Start with 50 free credits.
PromptLab Use Cases
Whether you're writing content, building apps, or analyzing data, PromptLab helps you generate, refine, and optimize prompts to get the best results—faster and more consistently.
A/B test inputs to create CTAs, headlines, and ad copy
Find the prompt that nails tone, style, and brand voice
Optimize blog intros, email sequences, and product descriptions
Use a dedicated Marketing Expert Agent to evaluate prompts
Why PromptLab?
Everything you need to write better prompts, test faster, and get results that actually matter.
Generate High-Quality Prompts Instantly
Craft effective prompts in seconds using proven frameworks powered by the latest in prompt engineering research and design.
Test Unlimited Variations Automatically
Mix and match system and user prompts to explore every possible combination—PromptLab does the heavy lifting for you.
Enhance Prompts With The Latest Research
Leverage a curated, always-evolving library of the latest prompt engineering techniques to enhance your inputs with cutting-edge best practices.
Flexible Payment Options
Start with 50 free credits, upgrade to Pro for 250 credits and the ability to connect your own API keys—choose the option that works best for you.
PromptLab Features
PromptLab provides every tool you need to engineer high-performing prompts–built into one seamless platform.
Credits & BYOK Options
Start with 50 free credits, upgrade to Pro for 250 credits and the ability to connect your own OpenAI, Anthropic, Google, or Fireworks API keys for maximum flexibility.
Experiment Builder
Design structured prompt experiments by combining system and user blocks with multiple variants. Instantly test all possible combinations across your selected AI models.
Chat Editor
Chat with your favorite LLMs—GPT-4o, Claude, Gemini, and more—all from a single interface. Pro subscribers can bring their own API keys and run multi-model tests without switching platforms.
Expert Agents
Leverage AI agents trained in domains like marketing, copywriting, software development, and more to evaluate prompts with contextual, expert-level accuracy.
Simple, transparent pricing
Choose the plan that fits your needs. Start free, upgrade when you're ready.
Free
Perfect for getting started with prompt engineering
- 50 one-time prompt credits
- Access to all AI models
- Basic experiment builder
- Chat editor interface
- Community support
Pro
Unlock the full potential of prompt optimization
- 250 prompt credits per month
- Bring your own API keys
- Unlimited chat history
- Advanced search & filters
- Expert agent evaluations
- Priority support
- Export experiment results (soon)
- Collaboration features (soon)
Need more credits? Purchase additional credits or upgrade to Pro to bring your own API keys from OpenAI, Anthropic, Google, or Fireworks for unlimited usage at your own cost.
What our users say
PromptLab is helping teams and individuals across industries create better prompts, faster.
PromptLab completely changed how I work with AI. I used to waste hours tweaking prompts—now I run full-scale tests across multiple models and know exactly what gets the best output.
Jasmine T.
Copywriter
As a developer building AI-driven apps, PromptLab is a game-changer. I can test prompt structures, switch models on the fly, and get fast, consistent feedback.
Derek L.
Developer
I use PromptLab to develop and refine educational prompts for course material. Being able to compare variations side-by-side has saved me time and improved quality.
Rachel A.
Course Designer
Frequently Asked Questions
Have questions about PromptLab? Find answers to common questions below.
Ready to engineer better prompts?
Start with 50 free credits to test and optimize your prompts across multiple AI models. No credit card required.
Upgrade to Pro for 250 monthly credits or bring your own API keys for unlimited flexibility.