Free · no signup
Free tools for people who ship prompts
Sharp, single-purpose tools for LLM engineers. Interactive ones run in your browser; the prompts work in any chat.
Which LLM should I use?
Pick your task and priority; get a recommended model, a cross-provider fallback chain, and a cost estimate.
interactiveLLM Token Counter
Paste text to estimate tokens, input cost across providers, and whether it fits each model’s context window.
interactiveModel Deprecation Checker
Check if a model is retired, deprecated, or legacy — and see the recommended replacement.
interactivePrompt Portability Linter
Paste a prompt, get an instant portability score and every provider-lock-in issue. Runs in your browser.
interactiveLLM Cost Calculator
Compare monthly cost across GPT-4o, Claude, Gemini and more — and see fallback + compression savings.
copy-paste promptThe Prompt-to-Spec Converter
Turn a vague ask into a rigorous, model-agnostic prompt spec — typed inputs, output contract, and eval checks.
copy-paste promptThe LLM Eval Rubric Generator
Generate automatic pass/fail eval checks — schema, contains, regex, length — for any prompt.
copy-paste promptThe Production Prompt Auditor
Audit any prompt for lock-in and token waste, get a model-agnostic rewrite and a fallback chain.
copy-paste promptThe LLM Fallback Chain Picker
Design a resilient, cost-aware cross-provider fallback chain for any task.
copy-paste promptThe Token-Waste Finder
Find the input tokens you pay for on every call that add nothing — and cut them.
These tools point at one thing
They help you make prompts portable, resilient, and cheap. VernaOne makes that permanent — every prompt a versioned, model-agnostic endpoint with automatic fallback, cost analytics, and lossless compression.
Try VernaOne free →Frequently asked
Are these LLM tools really free?
Yes — every tool here is free with no signup. The interactive tools run entirely in your browser; the copy-paste prompts work in any LLM.
Who makes these tools?
VernaOne — a prompt registry and multi-provider router (the "workbench for AI") that turns prompts into versioned, model-agnostic endpoints with automatic fallback and cost control.