Developer & Code Tools
25 tools for the small, constant tasks around actual coding: formatting a blob of JSON, decoding a token, testing a regex, checking whether a certificate is about to expire.
None of these need a build step or an account. Paste, convert, copy — most of them are built to answer one specific question you'd otherwise reach for a browser extension or a one-off script for.
Everything runs client-side using the browser's own APIs (JSON.parse, crypto.subtle, and similar), so nothing you paste — including tokens, hashes, or connection strings — leaves your browser.
Format & validate
6 toolsJSON Formatter
Validate and pretty-print JSON.
DEVXML to JSON Converter
Convert between XML and JSON.
DEVCSS Minifier
Minify or beautify a CSS file.
DEVJavaScript Minifier
Shrink a JS file for production.
DEVSQL Formatter
Beautify a messy SQL query.
DEVMarkdown to HTML
Live preview while you write Markdown.
Encode & convert
7 toolsBase64 Studio
Encode, decode and preview Base64 data.
DEVURL Encoder Decoder
Percent-encode or decode a URL.
DEVHTML Entity Encoder
Escape or unescape HTML entities.
DEVJWT Token Decoder
Inspect the header and payload of a JWT.
DEVNumber System Converter
Binary, hex, octal and decimal at once.
DEVASCII to Text Converter
Convert ASCII codes to readable text.
DEVEpoch Time Converter
Unix timestamp to and from a date.
Test & inspect
12 toolsRegex Tester
Test a pattern against sample text live.
DEVCode Diff Checker
Compare two code blocks side by side.
DEVCron Expression Parser
Plain-English explanation of a cron string.
DEVHash Generator
MD5, SHA-1 and SHA-256 from text.
DEVHMAC Generator
Generate an HMAC with a secret key.
DEVPassword Hash Checker
Check a password against a known hash.
DEVIP Subnet Calculator
CIDR range, mask and host count.
DEVDNS Lookup Tool
Look up records for a domain.
DEVSSL Certificate Checker
Check a certificate's validity and expiry.
DEVHTTP Status Checker
Check the status code a URL returns.
DEVWebsite Speed Tester
Basic load-time check for a page.
DEVBrowser Info Detector
See what a site can detect about your browser.
Frequently asked
Is it safe to paste real tokens, keys or connection strings into these?
The processing itself is safe — it happens in your browser and nothing is uploaded. That said, treat any secret the same way you would anywhere: prefer a test/dummy value when you're just checking that something parses correctly.
Do the network tools (DNS, SSL, HTTP status) actually reach the internet?
Yes — those specific tools make a real request to check the domain or URL you enter, since that's the only way to get an accurate answer. The formatters, converters and generators do not; they run entirely offline in your browser.