Everything a developer reaches for a dozen times a day, in one place and free. Encode and decode Base64 and URLs, format and convert JSON, YAML, CSV and XML, generate UUIDs and hashes, decode JWTs and timestamps, and build regexes without pasting private data into a sketchy website. Every tool runs entirely in your browser, so tokens, payloads and config never leave your machine. All 84 tools below are free, run in your browser, and need no sign-up.
Free Base64 encoder and decoder. Convert text to Base64 and decode Base64 back to text instantly in your browser. UTF-8 safe.
Free URL encoder and decoder. Percent-encode text for URLs or decode encoded URLs instantly. Handles query strings and special characters.
Free UUID generator. Instantly generate random v4 UUIDs (GUIDs), one or in bulk. Cryptographically random, copy with one click.
Free hash generator. Create SHA-1, SHA-256 and SHA-512 hashes from any text instantly in your browser using the Web Crypto API.
Free Unix timestamp converter. Convert epoch timestamps to human-readable dates and dates back to Unix time. Supports seconds and milliseconds.
Free JSON minifier. Strip whitespace and newlines to compress JSON into the smallest valid payload for APIs, configs and bundles. Validates as it minifies.
Free JSON validator. Check if your JSON is valid, get the exact error location on failure, and see a pretty-printed version when it parses cleanly.
Free JSON to CSV converter. Turn an array of JSON objects into a clean CSV file with headers, ready for Excel, Sheets or a database import.
Free CSV to JSON converter. Parse CSV with a header row into a clean array of JSON objects, handling quoted fields and embedded commas correctly.
Free JSON to YAML converter. Turn JSON config or API data into clean, readable YAML for Kubernetes, CI pipelines, Docker Compose and app config files.
Free YAML to JSON converter. Parse YAML config into clean JSON for APIs, tooling and validation. Handles nested maps, lists, comments and scalars.
Free XML formatter and beautifier. Pretty-print messy or minified XML with clean indentation so nested elements and attributes are easy to read.
Free YAML formatter. Normalize indentation and re-serialize your YAML into clean two-space output by round-tripping it through a parser. Catches errors too.
Free HTML formatter and beautifier. Indent messy or minified HTML into clean, readable markup with proper nesting so you can scan structure at a glance.
Free CSS formatter and beautifier. Expand minified CSS into clean, indented rules with one declaration per line so stylesheets are easy to read and edit.
Free JavaScript formatter and beautifier. Expand minified or one-line JS into readable, indented code with proper brace and block structure.
Free SQL formatter and beautifier. Turn long, cramped queries into clean, indented SQL with keywords on their own lines so complex statements are readable.
Free HTML entity encoder and decoder. Convert characters like < > & " to safe HTML entities and back, so text renders literally instead of as markup.
Free Unicode escape and unescape tool. Convert text to backslash-u escape sequences and back, ideal for embedding non-ASCII characters in JSON and source code.
Free hex to text converter. Decode hexadecimal byte sequences into readable text and encode text back to hex. UTF-8 safe, handles spaces and 0x prefixes.
Free binary to text converter. Decode 8-bit binary into readable text and encode text back to binary. UTF-8 safe, tolerant of spaces between bytes.
Free JWT decoder. Decode a JSON Web Token to inspect its header and payload claims instantly in your browser. Shows expiry in human-readable time.
Free regex tester. Test JavaScript regular expressions against sample text with live match highlighting, capture groups and flag toggles in your browser.
Free cron expression parser. Paste a cron schedule to get a plain-English explanation and the next upcoming run times, all computed in your browser.
Free visual cron builder. Pick minute, hour, day, month and weekday from dropdowns to generate a valid crontab expression with a live plain-English preview.
Free number base converter. Convert between binary, octal, decimal and hexadecimal instantly. Type in any base and see all four representations update live.
Free JSON diff tool. Compare two JSON objects and see added, removed and changed keys with their old and new values, computed entirely in your browser.
Free text diff checker. Compare two blocks of text line by line and see exactly which lines were added, removed or unchanged, computed in your browser.
Free gitignore generator. Select your languages, frameworks and tools to build a solid .gitignore file with sensible defaults, ready to copy into your repo.
Free chmod calculator. Toggle read, write and execute permissions for owner, group and others to get the octal chmod number and symbolic notation instantly.
Free subnet and CIDR calculator. Enter an IP with a CIDR prefix to get the network address, broadcast, usable host range, subnet mask and total hosts.
Free HTTP status codes reference. Search all standard HTTP response codes from 1xx to 5xx with their names and meanings. Filter instantly as you type.
Free MIME types reference. Search common file extensions and their content-type values for setting HTTP headers, uploads and downloads. Filter instantly.
Free ASCII table reference. Browse all 128 ASCII characters with their decimal, hexadecimal, octal and binary values plus names for control characters.
Free hex to RGB color converter for developers. Convert hex color codes to rgb() and back, with a live swatch preview and support for shorthand hex.
Free CSS minifier. Strip comments, whitespace and newlines to shrink stylesheets for faster page loads. Shows how many bytes you saved. Runs in your browser.
Free lightweight JavaScript minifier. Remove comments and collapse whitespace to shrink JS for quick inline use. Preserves strings and reports bytes saved.
Free SQL minifier. Collapse a multi-line SQL query into a single compact line by stripping comments and extra whitespace. Great for logs and embedding. Private.
Free JSON string escaper. Escape text into a safe JSON string literal, or unescape a JSON string back to raw text. Handles quotes, newlines and unicode. Private.
Free string length calculator. Count characters, bytes in UTF-8, words and lines in any string, with and without spaces. Useful for limits and encoding. Private.
Free Lorem Picsum URL builder. Configure width, height, grayscale, blur and a seed to generate ready-to-use random placeholder photo URLs for mockups. Private.
Free Base32 encoder and decoder. Convert text to standard RFC 4648 Base32 and decode it back. Handy for TOTP secrets, identifiers and case-insensitive tokens.
Free ROT47 encoder and decoder. Rotate printable ASCII by 47 positions to scramble text, including symbols and digits. Its own inverse, so one button does both.
Free query string parser. Paste a URL or query string and see every parameter and value in a clean table, with URL decoding and repeated keys handled. Private.
Free HTML table generator. Choose rows and columns, toggle a header row, and get clean, ready-to-paste HTML table markup with a live preview. Runs privately.
Free CSS box-shadow generator. Adjust offset, blur, spread, color and inset with live sliders and preview, then copy the ready-to-use box-shadow rule. Private.
Free meta tags generator. Enter your title, description and image to produce SEO, Open Graph and Twitter Card meta tags ready to paste into your page head. Private.
Free robots.txt generator. Pick which crawlers to allow or block, add disallow paths, crawl delay and a sitemap URL, then copy a valid robots.txt file. Private.
Free UUID v7 generator. Create time-ordered, sortable version-7 UUIDs in bulk. Great for database keys where insertion order and index locality matter. Private.
Free slugify tool. Turn any title or phrase into a clean URL-safe slug: lowercase, accents stripped, spaces and symbols collapsed into hyphens. Runs privately.
Free HTML to text converter. Strip tags and markup from HTML and get the clean plain text content, decoded and readable. All processing stays in your browser.
Free HMAC generator. Compute a keyed HMAC over any message with SHA-256, SHA-384 or SHA-512 using the Web Crypto API. Hex output, computed in your browser.
Free .env to JSON converter. Paste your dotenv KEY=VALUE lines and get a clean, pretty-printed JSON object. Comments and blank lines are ignored. Runs privately.
Free CSS unit converter. Convert px to rem and em, or rem and em back to px, with an adjustable root font size. Instant results, computed in your browser.
Free JWT generator. Build and sign a JSON Web Token from your payload and a secret using HS256 via the Web Crypto API. Pairs with the JWT decoder. Runs privately.
Free UUID validator. Paste a string to check whether it is a valid UUID and see which version (1 through 8) and variant it uses. Instant, private, in your browser.
Free string case converter for code. Turn any text into camelCase, snake_case, kebab-case, PascalCase or CONSTANT_CASE at once. Live, private, in your browser.
Free JSON to XML converter. Turn JSON objects and arrays into clean, indented XML for legacy APIs, SOAP services, config files and data feeds.
Free XML to JSON converter. Parse XML documents into clean, readable JSON with attributes and repeated elements handled correctly in your browser.
Free TSV to CSV converter. Turn tab separated values into proper comma separated CSV, quoting fields that contain commas, quotes or line breaks.
Free CSV to TSV converter. Turn comma separated values into tab separated text you can paste straight into spreadsheets, respecting quoted fields.
Free CSV to Markdown table converter. Turn CSV data into a clean GitHub flavored Markdown table with aligned columns for READMEs, docs and issues.
Free JSON to TypeScript converter. Generate a typed interface from a JSON sample, inferring nested objects, arrays and optional fields automatically.
Free JSON to Go struct converter. Generate typed Go structs with json tags from a JSON sample, inferring nested types, slices and field names.
Free JSON to PHP array converter. Turn JSON into a valid PHP array literal using short bracket syntax, ready to paste into a config or fixture file.
Free JSON unescape tool. Turn an escaped JSON string back into readable text, decoding backslash escapes, quotes, newlines and unicode sequences.
Free JSON to query string converter. Turn a JSON object into a URL encoded query string, flattening nested objects and arrays with bracket notation.
Free query string to JSON converter. Parse a URL query string into a clean JSON object, decoding values and grouping repeated keys into arrays.
Free JSON key sorter. Sort every object key alphabetically at all nesting levels for deterministic diffs, cleaner configs and reproducible output.
Free JSON flatten tool. Collapse a nested JSON object into flat dot notation keys, turning deep structures into a single level map for easy diffing.
Free JSON unflatten tool. Rebuild a nested JSON object from flat dot notation keys, expanding paths and array indices back into real structure.
Free NDJSON to JSON array converter. Turn newline delimited JSON into a single JSON array, parsing each line and reporting any bad rows clearly.
Free JSON array to NDJSON converter. Turn a JSON array into newline delimited JSON, one compact record per line, ready for streaming and log tools.
Free list to JSON array converter. Turn a plain list of lines into a JSON array of strings or numbers, trimming blanks and optionally deduplicating.
Free CSV column extractor. Pull a single column out of a CSV file by name or number, with a real parser that respects quoted fields and commas.
Free CSV to SQL insert generator. Turn CSV rows into ready to run INSERT statements with a header derived column list and safely quoted values.
Free JSON to HTML table converter. Turn an array of JSON objects into a clean HTML table with a header row and escaped cells, ready to paste anywhere.
Free JSON path extractor. Pull a value from deep inside JSON using a dot and bracket path like user.tags[0], with clear errors when a path is missing.
Free JSON stringify tool. Parse and re serialize JSON with a chosen indent, or produce an escaped single string value ready to embed in code.
Free fixed width to CSV converter. Split fixed column mainframe or report text into CSV by specifying column widths, trimming padding from each field.
Free JSON keys extractor. List every unique key path in a JSON document, including nested objects and arrays, so you can map or document a payload.
Free JSON to TOML converter. Turn JSON config into TOML tables and key value pairs for Rust, Python and other tools that read TOML config files.
Free CSV transpose tool. Flip rows and columns of a CSV so headers become the first column, using a real parser that respects quoted fields.
Free JSON to env file converter. Turn a flat JSON object into dotenv KEY=value lines, upper casing keys and quoting values that contain spaces.
Yes. Every tool in this toolkit is completely free, with no sign-up and no usage limits.
Yes. They run in any modern web browser on phone, tablet or desktop, with nothing to install.
Yes. These tools run entirely in your browser, so nothing you enter is uploaded to a server.