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Developer & Data Tools

Format, validate and convert JSON, Base64, CSV and SQL. Every tool runs in your browser, so internal data never leaves your machine

108 toolsNo signupRuns in your browser

JSON Formatter & Validator

Format, validate and minify JSON in your browser. Nothing is uploaded, so it is safe for internal API payloads. Free.

Base64 Encoder / Decoder

Encode and decode Base64 with full UTF-8 support, so accents, Chinese and emoji survive the round trip. Free and client-side.

SVG to CSS Background Converter

Turn SVG markup into a CSS background-image data URI you can paste straight into your stylesheet. Free, no signup.

Cron Expression Generator

Build a cron schedule with dropdowns and read it back in plain English. No more guessing what */15 2 * * 1-5 means. Free.

Binary, Hex and Decimal Converter

Convert numbers between binary, octal, decimal and hex — or any base from 2 to 36. One value per line. Free.

Find Common Items in Two Lists

Compare two lists and keep only the items they share. Separate the lists with --- on its own line. Free, no signup.

Find Items Missing From a List

Compare two lists and see what is in the first but missing from the second. Ideal for reconciliation. Free.

Merge Two Lists and Remove Duplicates

Combine two lists into one and drop every repeated entry. Separate the lists with --- on its own line. Free.

Filter Lines Containing Text

Keep only the lines that contain a keyword — or exclude them. Great for sifting log files and CSV dumps. Free.

Convert Lines to Comma Separated List

Turn a column of values into one comma-separated line ready for SQL, JavaScript or a spreadsheet formula. Free, nothing is uploaded.

Add Prefix and Suffix to Each Line

Wrap every line with a prefix, a suffix or both — perfect for turning values into quoted SQL strings or JSON keys. Free.

Character Counter

Count characters with and without spaces, plus words, lines and estimated reading time. Free and nothing is uploaded.

Clean Up Whitespace

Normalise line endings, strip trailing spaces and collapse runs of blank lines into one. Free, runs offline.

Remove All Spaces

Delete every space, tab and line break from a block of text, leaving one continuous string. Free, no signup.

Remove Line Numbers From Code

Strip the line numbers that get copied along with code from tutorials and diff views. Free, runs in your browser.

Add Line Numbers

Number every line in a list, starting from any value and using your own separator. Free, nothing is uploaded.

Compare Two Texts

See exactly what changed between two versions of a text, line by line. Separate them with --- on its own line. Free.

JSON to CSV Converter

Turn a JSON array into a CSV table, or paste CSV to get JSON back. Great for spreadsheets and APIs. Free, nothing is uploaded.

Unix Timestamp Converter

Convert a Unix timestamp to a readable date, or turn a date into a timestamp. Handles seconds and milliseconds. Free.

Hex, RGB and HSL Color Converter

Convert between hex, RGB and HSL so colours match across CSS, design tools and code. Free, runs offline.

URL Parser

Break any URL into its protocol, host, path, query and fragment. Perfect for debugging links. Free, no signup.

JWT Decoder

Decode a JSON Web Token to read its header and payload. The signature is not verified — inspect, do not trust. Free.

Query String Parser

Turn a ?key=value URL query string into a clean, readable list of parameters. Free, no signup.

HTML Minifier

Strip comments and extra whitespace from HTML to shrink the file and speed up your page. Free, runs offline.

CSS Minifier

Remove comments and unnecessary spaces from CSS to make it lighter to ship. Free, nothing is uploaded.

SQL Formatter

Pretty-print a messy one-line SQL statement so it is easy to read and review. Free, runs offline.

Regex Escape Tool

Escape special characters in a string so it can be used literally inside a regular expression. Free, no signup.

URL Decode

Turn percent-encoded text back into readable characters. Local, free, no signup.

HTML Encode

Escape <, >, &, quotes and apostrophes so text shows literally in HTML. Local, free, no signup.

HTML Decode

Convert HTML entities like & and < back to normal characters. Local, free, no signup.

Text to Hex

Show the hexadecimal byte representation of any text. Local, free, no signup.

Hex to Text

Decode a space-separated hex string back into readable text. Local, free, no signup.

Text to Binary

Convert any text into 8-bit binary groups per character. Local, free, no signup.

Binary to Text

Turn groups of binary digits back into text. Local, free, no signup.

Base64URL Encode

Encode text to URL-safe Base64, the variant used in JWTs and URLs. Local, free, no signup.

Base64URL Decode

Decode URL-safe Base64 back into text. Local, free, no signup.

Unicode Escape

Convert non-ASCII characters into \uXXXX escape sequences. Local, free, no signup.

Unicode Unescape

Turn \uXXXX escape sequences back into real characters. Local, free, no signup.

Caesar Cipher

Shift every letter by a chosen number of positions. Local, free, no signup.

Morse Code Encode

Translate letters and digits into Morse code dots and dashes. Local, free, no signup.

Morse Code Decode

Turn Morse code dots and dashes back into readable text. Local, free, no signup.

CSV to JSON

Convert a CSV table into an array of JSON objects using the header row as keys. Local, free, no signup.

JSON to XML

Convert a JSON object into a simple XML document. Local, free, no signup.

JSON to TOML

Convert JSON into TOML, the config format loved by Rust and Go tools. Local, free, no signup.

JSON to YAML

Convert JSON into clean, indented YAML. Local, free, no signup.

Sort JSON Keys

Recursively sort every object’s keys alphabetically for consistent diffs. Local, free, no signup.

JSON Validator

Check whether your JSON is valid and see the exact error if not. Local, free, no signup.

JSON to Query String

Flatten a flat JSON object into a URL query string. Local, free, no signup.

CSV to Markdown Table

Turn a CSV file into a GitHub-style Markdown table. Local, free, no signup.

Markdown Table to CSV

Convert a Markdown table back into plain CSV. Local, free, no signup.

CSV to HTML Table

Generate a ready-to-paste HTML table from a CSV file. Local, free, no signup.

CSV to SQL INSERT

Build INSERT statements from a CSV file for quick database seeding. Local, free, no signup.

Hex to RGB

Convert a hex color like #ff0000 into rgb(255, 0, 0). Local, free, no signup.

RGB to Hex

Convert rgb(255, 0, 0) into a hex color code. Local, free, no signup.

Hex to HSL

Convert a hex color into HSL (hue, saturation, lightness). Local, free, no signup.

HSL to Hex

Convert HSL values back into a hex color code. Local, free, no signup.

RGB to HSL

Convert RGB values into HSL. Local, free, no signup.

HSL to RGB

Convert HSL values into RGB. Local, free, no signup.

Hex to CMYK

Convert a hex color into print-friendly CMYK percentages. Local, free, no signup.

CMYK to Hex

Convert CMYK percentages back into a hex color. Local, free, no signup.

Sort Lines A–Z

Sort all lines alphabetically, ascending. Local, free, no signup.

Sort Lines Z–A

Sort all lines alphabetically, descending. Local, free, no signup.

Sort & Unique Lines

Sort lines and remove duplicates in one step. Local, free, no signup.

Remove Empty Lines

Delete lines that are blank or only whitespace. Local, free, no signup.

Extract Phone Numbers

Find phone-number-like sequences in any text. Local, free, no signup.

Extract IP Addresses

Pull IPv4 addresses out of logs and text. Local, free, no signup.

Keep Only Numbers

Remove everything except digits, dots and spaces. Local, free, no signup.

Strip HTML Tags

Remove all HTML tags and keep only the visible text. Local, free, no signup.

Strip ANSI Codes

Remove terminal color and style escape codes from logs. Local, free, no signup.

Normalize Unicode (NFC)

Combine decomposed characters into their canonical form. Local, free, no signup.

Find & Replace

Replace every occurrence of a substring, with optional case insensitivity. Local, free, no signup.

Word & Character Count

Count words, characters, characters without spaces and lines. Local, free, no signup.

Palindrome Checker

Test whether a phrase reads the same forwards and backwards. Local, free, no signup.

Vowel Counter

Count how many vowels (a, e, i, o, u) appear in your text. Local, free, no signup.

Reverse Word Order

Flip the order of words in a sentence, keeping each word intact. Local, free, no signup.

Wrap Text

Re-flow text to a maximum line width, breaking on word boundaries. Local, free, no signup.

Indent Text

Add a fixed number of spaces to the start of every line. Local, free, no signup.

CSS Beautifier

Re-format minified CSS with one rule per line and indentation. Local, free, no signup.

HTML Beautifier

Indent HTML tags so the document structure is easy to read. Local, free, no signup.

SQL Minifier

Strip comments and extra whitespace from SQL to shrink it. Local, free, no signup.

XML Beautifier

Indent XML elements for readable, well-structured documents. Local, free, no signup.

XML Minifier

Remove whitespace between tags to make XML compact. Local, free, no signup.

Decimal to Roman

Convert a number from 1 to 3999 into Roman numerals. Local, free, no signup.

Roman to Decimal

Convert a Roman numeral back into a normal number. Local, free, no signup.

Number to Binary

Convert a decimal integer into its binary representation. Local, free, no signup.

Number to Hex

Convert a decimal integer into hexadecimal. Local, free, no signup.

Number to Octal

Convert a decimal integer into octal (base 8). Local, free, no signup.

Epoch to Date

Convert a Unix timestamp (seconds or milliseconds) into a readable date. Local, free, no signup.

Date to Epoch

Convert a date and time into a Unix timestamp in milliseconds. Local, free, no signup.