Free Developers Tools
JSON, JWT, IPv4/CIDR, password entropy, bandwidth, regex, and more
- Runs entirely in your browser
- No signup required
- SEO guides and FAQs on every tool page
13 tools in this category
JSON Formatter
Format, minify, and validate JSON in your browser
OpenJWT Decoder
Decode JWT tokens locally — nothing is sent to a server
OpenBase64 Encode/Decode
Encode and decode text with Base64
OpenCron Expression Builder
Build and explain cron schedules
OpenUUID Generator
Generate cryptographically random UUID v4 values
OpenTimestamp Converter
Convert Unix timestamps to dates and back
OpenHash Generator
SHA-256, SHA-384, and SHA-512 hashing in the browser
OpenRegex Tester
Test JavaScript regular expressions against sample text
OpenSubnet Calculator
Number of usable hosts
OpenIPv4 Range
Network, broadcast, and hosts from CIDR
OpenTransfer Time
File transfer time from link speed
OpenPassword Entropy
Strength in bits from character set
OpenCSS clamp() Helper
Build a fluid clamp() from min, preferred, and max sizes
OpenLooking for something else? Browse all tools or explore curated hubs.