All Free Online Tools
Browse every OmniTool: developer tools, image compressors and PDF utilities. All run locally in your browser — nothing is uploaded.
Developer Tools
8JSON Formatter
Format, validate and minify JSON in your browser. No data is ever uploaded.
JSON Diff
Compare two JSON documents side by side and see differences instantly.
JWT Decoder
Decode JWT tokens, inspect the header and payload, and verify signatures.
Base64 Encoder/Decoder
Encode text or files to Base64, or decode Base64 back to readable text.
Hash Generator
Generate SHA-1/256/384/512 and MD5 hashes using your browser Web Crypto.
UUID Generator
Generate cryptographically secure random UUID v4 / GUID values in bulk.
Chinese to Pinyin
Convert Chinese characters to pinyin with automatic polyphonic disambiguation.
Cron Expression Parser
Parse cron expressions into a human-readable schedule with next run times.
Network Tools
5URL Encoder / Decoder
Encode or decode URLs and URL components with configurable options.
Subnet / CIDR Calculator
Compute network, broadcast, mask and host ranges from any CIDR block.
HTTP Status Codes
Look up the meaning of any HTTP status code, grouped by class.
Common Ports Lookup
Find the service behind well-known TCP and UDP ports.
IP Address Converter
Validate IPv4/IPv6 addresses and convert between decimal, binary and hex.
Time & Date
5Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates, in seconds or milliseconds.
Date Formatter
Format any date with common presets or your own YYYY-MM-DD template.
Time Zone Converter
Convert a time between any two time zones and see multiple world clocks at once.
Date Difference Calculator
Calculate the exact difference between two dates in years, months and days.
Relative Time Converter
Turn a date into friendly relative time like "3 hours ago" or "in 2 days".
Image & Media
2PDF & Documents
2🔒 Privacy: all processing happens locally in your browser. Nothing is uploaded.
22 tools · Free, private, all in your browser.