Dev Tools
Dev Tools tools on UniTools: JSON formatter, password generator and more.
The Dev Tools category focuses on practical browser-based utilities for JSON cleanup, password creation, and subnet calculation.
The goal is fast utility work with minimal UI and direct output.
Tools in this category
JSON formatter and validator
Paste raw JSON to indent it readably, or find out exactly where it breaks. Runs in your browser, so payloads never leave the machine.
Password Generator
Build a strong password with the character sets you choose. Generated in your browser and never sent over the network.
Subnet Calculator
Enter an IPv4 address and prefix to get the network address, broadcast address, usable host range and host count.
Base64 Encoder / Decoder
Encode text to Base64 or decode it back, handling Cyrillic, accents and emoji correctly. Everything happens in your browser.
URL Encoder / Decoder
Encode query parameters and paths, or decode a URL full of %20s. Choose between encoding a component or a whole URI.
UUID Generator
Generate random UUID version 4 identifiers using your browser's cryptographic random source. Bulk generation up to 50 at once.
Unix Timestamp Converter
Convert Unix timestamps to readable UTC dates or turn a date into epoch seconds. Detects automatically whether you pasted seconds or milliseconds.
Color Converter (HEX, RGB, HSL)
Convert a hex colour to RGB and HSL, or build one from RGB values. HSL is the format that makes lighter and darker variants trivial.
JWT Decoder
Decode a JSON Web Token to inspect its header, claims and expiry. Runs entirely in your browser, so tokens are never transmitted.
Cron Expression Parser
Break a cron expression into its five fields and read what each one does, so you know when the job really runs.
HTML Entities Encoder
Convert angle brackets, ampersands and quotes into HTML entities, or decode entities back into readable text.
Query String Parser
Split a URL into its query parameters and decode them, so percent-encoded values become readable text.
Random String Generator
Generate random strings of any length from several alphabets, with an entropy estimate and an optional prefix.
Hash Generator
Computes SHA-256, MD5 and CRC32 of any string in the browser — nothing is sent anywhere.
Regex Tester
Shows every match and its position, the capture groups, and the result of a replacement.
Markdown to HTML Converter
Turns headings, lists, links, code and emphasis into clean HTML with no extra classes or wrappers.
JSON to YAML Converter
Converts configuration between JSON and YAML in both directions, validating the source as it goes.
CSV to JSON Converter
Turns a table into an array of objects and back, with a configurable delimiter and automatic number detection.
SQL Formatter
Breaks a query at its keywords, pulls conditions and column lists onto their own lines, and lists the tables involved.
Colour Contrast Checker
The contrast ratio between text and background and whether it meets accessibility levels AA and AAA.
CSS Gradient Generator
Ready CSS for linear, radial and conic gradients, with a midpoint stop and a solid fallback colour.
UTM Link Builder
Assembles a URL with UTM parameters, normalises the values to one spelling and warns when the link gets too long.
Meta Tag Length Checker
Measures meta tags in characters and in pixels and warns whether search results will truncate them.
Robots.txt Generator
Builds a robots.txt file with the disallow rules you need, a sitemap line, a preferred host and a crawl delay.
Open Graph Generator
Builds Open Graph and Twitter Card meta tags so a link unfurls with a picture and a description wherever it is shared.
JSON-LD FAQ Generator
Builds FAQPage structured data in JSON-LD from a list of questions and answers, ready to paste into a page.
Redirect Rule Generator
Builds a redirect rule for nginx, Apache or Next.js with the response code you choose.
HTTP Status Code Lookup
Explains a server response code, its family, its effect on indexing and its default caching behaviour.
Related categories
FAQs
What tools are included in Dev Tools?+
JSON formatting and validation, password generation, and IP/CIDR subnet calculation.
Is data sent to an external service?+
Core dev-tool workflows are designed to run locally in the browser.
Is this category meant for daily workflow tasks?+
Yes. These pages are built for short practical sessions without heavy navigation.
Does each tool have its own route?+
Yes. Every tool in the category has a dedicated URL and SEO block.