Free Converter Online — fast, private tools for everyday tasks
A growing collection of free online converters, calculators, and generators that run directly in your browser. No signup, no tracking, and your data never leaves your device.
Most tools run 100% in your browser — your input is never uploaded or logged.
Most popular tools
LLM Token Counter
Count tokens for GPT, Claude, Gemini, Llama, and Mistral with live cost estimate
LLM Cost Calculator
Compare API cost across GPT, Claude, Gemini, Llama and Mistral for a given token budget
Context Window Fit Checker
Check whether system + history + prompt fit any model context window, with output headroom
Prompt Caching Savings
Estimate how much prompt caching saves on Claude, GPT and Gemini at a given cache hit rate
Embeddings Cost Calculator
Estimate cost to embed a corpus with OpenAI, Voyage, Gemini or Mistral embedding models
RAG Chunk Estimator
Estimate chunks, embedding cost and per-query LLM cost for a RAG pipeline end-to-end
JSON to YAML
Convert JSON data to clean, human-readable YAML format
JSON Beautify
Pretty-print and format minified JSON with proper 2-space indentation in your browser
QR Code Generator
Create QR codes for URLs, Wi-Fi, email, phone, and plain text
Barcode Generator
Generate Code 128, EAN, UPC & more barcodes as PNG or SVG
Password Generator
Generate strong, cryptographically secure passwords and passphrases
UUID Generator
Generate cryptographically random UUID v4 identifiers
Text to Base64
Encode any text to Base64 — fast, free Base64 encoder