Base64 Encode & Decode
EncodingConvert text to Base64 and back, with URL-safe output. UTF-8 correct (emoji included), 100% in your browser.
Open tool →JSON Formatter & Validator
FormatBeautify, minify, validate and key-sort JSON, with the line and column of any syntax error.
Open tool →Unix Timestamp Converter
TimeEpoch ↔ human date (UTC/ISO) in seconds or milliseconds, with the live current Unix time.
Open tool →Cron Expression Generator
SchedulingBuild a cron schedule, read it in plain English and preview the next five run times in UTC.
Open tool →URL Encoder & Decoder
EncodingPercent-encode/decode (component or whole URL) and break a URL into its parts and query parameters.
Open tool →Regex Tester
TextTest regular expressions live with flags, highlighted matches, capture groups and a match map.
Open tool →JWT Decoder
SecurityDecode a JWT’s header and payload with human-readable iat/exp/nbf dates and an expiry check.
Open tool →Developer tools that respect your data
This collection brings the everyday utilities developers and sysadmins reach for — encoding, formatting, time conversion, scheduling and token inspection — into one fast, consistent place. Every tool is client-side: your input is processed by JavaScript in your own browser, so it is never sent to a server. That makes them safe for config, tokens and other sensitive text.
They sit alongside Servnet’s other free calculators — for storage, networking, power and security. Browse everything on the free tools directory.
Developer tools — common questions
Are these developer tools really free?
Yes — every tool here is free to use with no sign-up, no limits and no ads tracking you. Servnet builds them as a resource for the developer and IT community.
Do the tools send my data anywhere?
No. Each tool runs entirely in your browser using JavaScript, so the text, JSON, tokens or URLs you paste never leave your device. That makes them safe for sensitive data.
Do I need to install anything?
No installation and no extension — open a tool and use it. They work on desktop and mobile, and most keep working even if you go offline after the page has loaded.
Who is behind these tools?
Servnet is a UK IT reseller and services company established in 2001, providing servers, storage, networking and security. These tools complement our free storage, networking, power and security calculators.