Convert, Encode & Estimate AI Costs — Fast, Free, Private
Developer tools that run entirely in your browser. No signup, no uploads — your data stays on your device. Plus AI products for sellers and builders.
🛠 Free Developer Tools
Cron Expression Generator
Create and explain cron expressions with a visual builder. Understand what every field means in plain language.
YAML to JSON Converter
Convert YAML to JSON and JSON to YAML instantly. Syntax errors highlighted with clear messages.
Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and back. Supports seconds and milliseconds.
Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to text. UTF-8 safe with automatic direction detection.
SHA256 Hash Generator
Generate SHA-256 hashes from text or files right in your browser using the native Web Crypto API.
AI API Cost Calculator
Estimate LLM API costs across 23 providers (OpenAI, Anthropic, DeepSeek, Gemini). Plan your budget before you build.
Review Sentiment Analyzer
Paste a customer review and get instant AI sentiment analysis — score, themes, and highlights. Powered by DeepSeek.
Content Repurposer
Turn a blog post into a Twitter thread + LinkedIn post + summary. AI-powered, free.
Website Conversion Checker
Free automated CRO audit — 8 checks (title, CTA, mobile, trust, speed). Instant score for any landing page.
Our Products — AI Tools for Sellers & Developers
The ToolMatrix ecosystem: free tools here, full-powered products here.
ListingAI
AI-powered Amazon/eBay listing generator for cross-border sellers. Create optimized listings in seconds.
ReviewPilot
Turn customer reviews into actionable insights. Identify top issues and get improvement suggestions.
VSCode AI Cost Tracker
Track AI API costs right inside VS Code. Real-time cost per call, budgets, and project stats.
TokenTracker
Monitor AI token usage and costs across all your tools. Chrome extension for AI API cost tracking.
Why Use ToolMatrix?
Private by Design
All tools run locally in your browser. Your text and files stay on your device.
Free Forever
No accounts, no paywalls, no usage limits on any of our core tools.
Developer-First
Built for developers by developers. Clean output, copy buttons, and keyboard-friendly.