Craft. Combine. Compare. Evolve your prompts.

PromptKenstein is your experimental playground for building, managing, and comparing prompts across different LLMs. No sales pitch—just free tools for geeky minds.

Feature 01

Modular Prompt Builder

Combine different versions of prompts like Lego bricks. Use header from Prompt A v1 and body from Prompt B v3—mix, match, and experiment away.

Feature 02

LLM Playground with Superpowers

Run your prompt across multiple LLMs in parallel, see output side by side, compare latencies, token usage, and total generation time.

Feature 03

Version Control for Prompts

Keep track of your edits with Git-style versioning. Every change is logged so you can roll back or compare versions anytime.

Feature 04

Side-by-Side Diff Viewer

Instantly see what changed between prompt versions—visually and structurally. No more guessing what went wrong.

Feature 05

Latency Tracking & Token Insights

Dive into performance metrics with detailed latency, token usage, and cost breakdown per provider and model.

Feature 06

Just Use It, No Strings Attached

PromptKenstein is free to use. No pricing tiers, no credit cards. Just sign in and start crafting smarter prompts.

How it works

Take a peek at how PromptKenstein helps you experiment better. From prompt building to version diffing, here’s what it looks like in action.

Build prompts like blocks
Test across GPT, Claude, Mistral at once
Track token cost and latency
View diffs between prompt versions
Easily revert or share a version

Just log in and play.