Is it safe to paste production data, tokens or code into these tools?

The text is processed by JavaScript in your own browser tab and is not sent to Stax, so nothing leaves your device through the tool. You can check this yourself: open your browser's developer tools, switch to the Network tab and use a tool, and you will see no request that carries your input. As a general habit, avoid pasting live secrets into any web page. For a JWT, decoding shows what the token claims but proves nothing about whether it is genuine.

What is the difference between formatting, validating and minifying?

Formatting (or beautifying) adds indentation and line breaks so a person can read the data. Minifying removes unnecessary whitespace so it is as small as possible. Validating checks that the text follows the language's rules. The JSON, XML, HTML and SQL tools format and minify, and the JSON and XML tools also validate.

Which tool is for encoding and which is for hashing?

Encoding such as Base64, URL encoding or HTML entities only changes how data is written so that it can travel safely. It is not encryption and anyone can reverse it. A hash such as SHA-256 turns data into a fixed-length fingerprint that cannot be reversed, which is what you use to compare files or check a download. The hash generator produces SHA-1, SHA-256, SHA-384 and SHA-512.

Why does my Unix timestamp show the wrong year?

A timestamp in seconds has about ten digits and one in milliseconds has about thirteen. Reading a millisecond value as seconds puts the date thousands of years in the future. The timestamp converter supports both units, so paste the number as it is and check which unit the result assumed.

Do the tools cope with very large inputs?

They run on your device, so the limit is your browser's memory, not a server cap. Inputs of several megabytes are normally fine. If a page slows down or a tab stops responding on a very large file, split the data or use a command-line tool for that one job.

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Free Developer Tools

Most developer chores are small and repetitive: a response body that arrives as one unreadable line, a token you want to look inside, a pattern that almost matches, a timestamp that could be seconds or milliseconds. These tools handle those jobs without an install, an account or a browser extension, and the text you paste is processed by your own browser rather than sent to a server.

The collection falls into a few groups: formatters and validators (JSON, XML, HTML, SQL), converters (JSON to CSV, YAML, TOML or TypeScript types, number bases, colour formats), encoders and hashes (Base64, URL, HTML entities, Unicode, SHA hashes, UUIDs, JWTs), time and scheduling (timestamps, time zones, cron), CSS generators, and quick-reference cheat sheets for regex, Git, SQL, Flexbox, Grid and more.

72 tools available

Most Popular

JSON Formatter

Format, beautify, minify, and validate JSON in your browser

Try it free →Regex Tester

Test regular expressions with live match highlighting and capture groups.

Try it free →JWT Decoder

Decode JWT tokens and inspect header, payload, and expiry. Runs in-browser.

Try it free →

Which tool should I use?

A response or config file is one long line: JSON Formatter — formats, minifies and validates JSON in one place.
Deeply nested JSON is hard to read: JSON Tree Viewer — shows it as a collapsible tree with colour-coded types.
You need TypeScript types from a JSON sample: JSON to TypeScript Generator — builds interfaces for nested objects, arrays and union types.
A JSON array has to become a spreadsheet: JSON to CSV Converter — writes CSV with standard quoting you can download or copy.
A CSV export has to become JSON: CSV to JSON Converter — handles any delimiter and quoted fields.
Moving config between JSON, YAML and TOML: JSON ↔ YAML ↔ TOML Converter — converts in either direction with one swap button.
Looking inside a JWT: JWT Decoder — shows the header, payload and expiry.
Writing or debugging a regular expression: Regex Tester — highlights matches and capture groups as you type.
Understanding a cron schedule: Cron Expression Parser — turns an expression into plain English and the next run times.
Making a fingerprint of text: Hash Generator — produces SHA-1, SHA-256, SHA-384 and SHA-512.
A timestamp that looks wrong: Timestamp Converter — reads seconds and milliseconds and converts both ways.
Comparing two versions of a text: Diff Checker — shows line by line what changed.
Testing an upload limit: Test File Generator — makes a valid PDF, image, CSV, JSON or ZIP of an exact size.

All Developer Tools (72)

JSON Formatter

Format, beautify, minify, and validate JSON in your browser

Open tool →QR Code Generator

Generate QR codes for URLs, text, Wi-Fi, and more. Download as PNG.

Open tool →Password Generator

Generate strong, random passwords with custom length and character sets.

Open tool →Base64 Encoder / Decoder

Encode text to Base64 or decode Base64 back to plain text. Supports Unicode.

Open tool →URL Encoder / Decoder

Encode or decode URLs and query strings with percent-encoding.

Open tool →Hash Generator

Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes instantly.

Open tool →Color Picker

Pick any color and instantly get HEX, RGB, and HSL values.

Open tool →Regex Tester

Test regular expressions with live match highlighting and capture groups.

Open tool →Text Case Converter

Convert text to camelCase, PascalCase, snake_case, kebab-case, and more.

Open tool →Timestamp Converter

Convert Unix timestamps to dates and vice versa. Supports seconds and milliseconds.

Open tool →Lorem Ipsum Generator

Generate custom Lorem Ipsum placeholder text — choose number of paragraphs, sentences, or words. Pure client-side.

Open tool →Number Base Converter

Convert numbers between binary, octal, decimal, and hexadecimal instantly.

Open tool →JWT Decoder

Decode JWT tokens and inspect header, payload, and expiry. Runs in-browser.

Open tool →UUID Generator

Generate cryptographically secure UUID v4 values. Bulk generate up to 50 at once.

Open tool →CSS Gradient Generator

Build linear and radial CSS gradients visually and copy ready-to-use CSS.

Open tool →JSON to CSV Converter

Convert JSON arrays to CSV with RFC 4180 quoting. Download or copy instantly.

Open tool →Diff Checker

Compare two texts line by line and see exactly what changed. LCS-based diff.

Open tool →Unit Converter

Convert length, weight, temperature, area, volume, speed, and data units.

Open tool →Random Number Generator

Generate secure random numbers in any range. Bulk generate up to 1000 at once.

Open tool →Time Zone Converter

Convert time between IST, UTC, EST, PST, Dubai, Singapore, Tokyo and more.

Open tool →Cron Expression Parser

Parse cron expressions into plain English and preview the next 5 execution times.

Open tool →Cron Expression Builder

Build and validate cron expressions visually — minute, hour, day, month, weekday fields with human-readable preview. No signup required.

Open tool →Image to Base64 Converter

Convert any image to Base64 or Data URI instantly in your browser. 100% private.

Open tool →Aspect Ratio Calculator

Calculate, simplify, and scale aspect ratios for video, photo, and design.

Open tool →Text to Slug Generator

Convert any title or text into a clean, SEO-friendly URL slug.

Open tool →Number to Words Converter

Convert numbers to words in Indian (Lakh/Crore) or International format. Cheque-ready output.

Open tool →Password Strength Checker

Check password strength with real-time score, crack time estimate, and improvement tips.

Open tool →Morse Code Translator

Translate text to Morse code or decode Morse back to text. Includes full reference chart.

Open tool →Font Size Converter

Convert CSS font sizes between px, rem, em, pt, vw, vh, and % with custom viewport settings.

Open tool →CSV to JSON Converter

Convert CSV data to JSON array instantly. Supports all delimiters and quoted fields.

Open tool →Color Contrast Checker

Check WCAG AA and AAA colour contrast ratios for web accessibility compliance.

Open tool →Binary Text Converter

Convert text to binary, hex, or octal — and decode back to text.

Open tool →HTML Entity Encoder / Decoder

Encode HTML special characters to entities or decode HTML entities to plain text.

Open tool →Scientific Calculator

Free online scientific calculator with trigonometry, logarithms, powers, factorials, and constants π and e.

Open tool →Color Palette Generator

Generate 10 lightness shades and 10 harmonic colours (complementary, triadic, analogous) from any hex colour.

Open tool →Chmod Calculator

Calculate Unix/Linux file permissions visually. Get octal value and ready-to-run chmod command for any permission set.

Open tool →HEX to RGB Converter

Convert colour codes between HEX, RGB, RGBA, HSL, HSLA, and HSV instantly with live sliders. Click to copy any format.

Open tool →Roman Numeral Converter

Convert numbers to Roman numerals or decode Roman numerals to numbers. Supports 1–3999 with full reference chart.

Open tool →Date Difference Calculator

Calculate exact days, weeks, months, years, and working days between any two dates. Shows countdown for future dates.

Open tool →Random Color Generator

Generate random colour palettes in random, pastel, vivid, dark, or monochrome styles. Lock colours and copy hex codes.

Open tool →JSON to TypeScript Generator

Convert JSON objects to TypeScript interfaces instantly. Supports nested objects, arrays, union types, and custom root names.

Open tool →Email Validator

Validate email addresses with a 9-point checklist, quality score, and disposable domain detection. Bulk validation supported.

Open tool →Online Stopwatch

Free online stopwatch with lap timer. Records fastest and slowest laps with centisecond precision. Works in-browser.

Open tool →IP Subnet Calculator

Calculate IPv4 subnet details from CIDR notation — network address, broadcast, usable hosts, subnet mask, wildcard mask, and IP class.

Open tool →Unicode Converter

Convert text to Unicode code points and back. Inspect UTF-8/UTF-16 bytes and generate JS, CSS, HTML, and Python escape sequences.

Open tool →Number Formatter

Format numbers for any locale — Indian lakh/crore, US, European, Arabic. Supports currency, percent, scientific, and compact notation.

Open tool →HTML Formatter & Beautifier

Format, beautify, and minify HTML instantly in your browser. Indent HTML with 2 or 4 spaces with tag stats. 100% client-side.

Open tool →CSS Box Shadow Generator

Generate CSS box-shadow visually with live preview. Control X/Y offset, blur, spread, color, opacity, and inset. Supports multiple layers.

Open tool →XML Formatter & Validator

Format, beautify, minify, and validate XML in your browser. Supports RSS, SOAP, SVG, config files. 100% client-side.

Open tool →JSON Tree Viewer

Visualise JSON as an interactive collapsible tree. Colour-coded data types, expandable nodes for nested objects and arrays.

Open tool →CSS Flexbox Playground

Experiment with Flexbox properties visually — flex-direction, justify-content, align-items, flex-wrap, align-content, and gap. Copy the generated CSS.

Open tool →CSS Grid Generator

Build CSS Grid layouts visually with live preview. Set columns, rows, gap, and alignment. Copy the generated grid CSS instantly.

Open tool →SQL Formatter & Beautifier

Format, beautify, and minify SQL queries online. Keyword capitalisation, consistent indentation, and one-click copy. 100% client-side.

Open tool →SVG to PNG Converter

Convert SVG to PNG online. Paste SVG code or upload a file, choose scale (1×–4×) and background, and download a high-resolution PNG.

Open tool →Favicon Generator

Generate favicons in all sizes (16 to 512px) from text or an uploaded image. Download PNGs and copy the HTML link tag snippet.

Open tool →JSON ↔ YAML ↔ TOML Converter

Convert between JSON, YAML, and TOML data formats instantly in your browser. Swap input and output formats with one click. 100% client-side.

Open tool →Barcode Generator

Generate barcodes online — CODE128, EAN-13, EAN-8, UPC, CODE39, ITF-14, and more. Customise colors, size, and download as SVG.

Open tool →Regex Cheat Sheet

Quick reference for regular expressions: anchors, character classes, quantifiers, groups, lookarounds, flags, and ready-to-use patterns.

Open tool →Markdown Cheat Sheet

Complete markdown reference: headings, emphasis, lists, links, code blocks, tables, and GFM extensions like task lists and strikethrough.

Open tool →Chmod Cheat Sheet

Quick reference for Unix file permissions: octal notation (777, 755, 644), symbolic notation (rwx), special bits, and recursive command patterns.

Open tool →CSS Flexbox Cheat Sheet

Complete Flexbox reference: container properties, item properties, common patterns (centering, navbar, equal columns), and gotchas.

Open tool →JSON Cheat Sheet

JSON syntax reference: data types, escape characters, JSON5 differences, common pitfalls (trailing commas, comments, NaN), and date conventions.

Open tool →CSS Grid Cheat Sheet

Complete CSS Grid reference: container properties, item placement, grid-template-areas, fr/minmax/auto-fit, and Grid vs Flexbox decision guide.

Open tool →SQL Cheat Sheet

Comprehensive SQL reference: SELECT, JOINs, GROUP BY, window functions, CTEs, INSERT/UPDATE/DELETE, indexes, and PostgreSQL/MySQL/SQLite differences.

Open tool →Git Cheat Sheet

Practical Git command reference: branch, commit, rebase, merge, stash, cherry-pick, undo recipes, and the 10 commands that solve 95% of problems.

Open tool →JSONLint Alternative

JSONLint vs Stax JSON Formatter — feature comparison, privacy comparison, and when to pick which. Free, browser-only.

Open tool →regex101 Alternative

regex101 vs Stax Regex Tester: what each does, which engines they cover and how they handle your test text. Browser-based.

Open tool →jwt.io Alternative

jwt.io vs Stax JWT Decoder: what each does with a token, and how Stax decodes in your browser next to Base64, hash and regex tools.

Open tool →JavaScript Cheat Sheet

Complete JavaScript reference: variables, arrays, objects, functions, promises, async/await, ES2024 features, DOM, error handling. Bookmark-ready quick reference.

Open tool →Test File Generator

Make a dummy PDF, image, CSV, JSON, ZIP or text file of an exact size to test an upload, in your browser.

Open tool →Zip Files Online

Put several files or a folder into one ZIP in your browser, with nothing uploaded.

Open tool →Unzip Files Online

Open a ZIP or GZ file, see what is inside and save the files you want, with nothing uploaded.

Open tool →

Also useful

Sample PDF files, exact sizes

Valid PDFs from 100 KB to 100 MB, built in your browser, with the upload limits each size meets.

Open →

Frequently Asked Questions

Is it safe to paste production data, tokens or code into these tools?: The text is processed by JavaScript in your own browser tab and is not sent to Stax, so nothing leaves your device through the tool. You can check this yourself: open your browser's developer tools, switch to the Network tab and use a tool, and you will see no request that carries your input. As a general habit, avoid pasting live secrets into any web page. For a JWT, decoding shows what the token claims but proves nothing about whether it is genuine.
What is the difference between formatting, validating and minifying?: Formatting (or beautifying) adds indentation and line breaks so a person can read the data. Minifying removes unnecessary whitespace so it is as small as possible. Validating checks that the text follows the language's rules. The JSON, XML, HTML and SQL tools format and minify, and the JSON and XML tools also validate.
Which tool is for encoding and which is for hashing?: Encoding such as Base64, URL encoding or HTML entities only changes how data is written so that it can travel safely. It is not encryption and anyone can reverse it. A hash such as SHA-256 turns data into a fixed-length fingerprint that cannot be reversed, which is what you use to compare files or check a download. The hash generator produces SHA-1, SHA-256, SHA-384 and SHA-512.
Why does my Unix timestamp show the wrong year?: A timestamp in seconds has about ten digits and one in milliseconds has about thirteen. Reading a millisecond value as seconds puts the date thousands of years in the future. The timestamp converter supports both units, so paste the number as it is and check which unit the result assumed.
Do the tools cope with very large inputs?: They run on your device, so the limit is your browser's memory, not a server cap. Inputs of several megabytes are normally fine. If a page slows down or a tab stops responding on a very large file, split the data or use a command-line tool for that one job.