Tools

Developer tools

Everyday utilities for developers: format and validate JSON, encode and decode Base64 and URLs, decode JWTs, generate hashes and UUIDs, test regular expressions and compare text. Everything runs locally in the browser.

109 showing

01 Number Base Converter Convert between bases 2 through 36.math02 JSON Formatter Pretty-print JSON with a chosen indent.developer03 JSON Minifier Strip insignificant JSON whitespace.developer04 JSON Validator Tell whether a document is valid JSON.developer05 JSON Tree Viewer Expand objects and arrays and copy a path.developer06 JSON Diff Structural additions, removals and changes.developer07 JSON Path Tester Query a document with JSONPath.developer08 JSON to TypeScript Infer an interface from a JSON sample.developer09 JSON to CSV Turn an array of objects into CSV.converter10 CSV to JSON Parse CSV, including quoted commas.converter11 XML Formatter Pretty-print XML and check that tags balance.developer12 YAML Formatter Parse YAML and print it in a stable form.developer13 Unix Timestamp Converter Seconds, milliseconds, ISO and local time.developer14 Color Format Converter HEX, RGB and HSL from one value.developer15 Color Picker Pick a color and read its channels.developer16 Contrast Checker WCAG contrast for two colors.developer17 Base64 Encode / Decode UTF-8 Base64, including URL-safe.developer18 URL Encode / Decode Percent-encode and decode a URL component.developer19 HTML Entity Encode / Decode Escape and unescape HTML characters.developer20 Unicode Inspector Code point, UTF-8 bytes and block for each character.developer21 JWT Decoder Read the header and payload. The signature is not verified.developer22 Hex to Text Text to hexadecimal and back.developer23 Binary to Text Bytes as 8-bit groups, and the reverse.developer24 HTML Formatter Format or minify HTML.developer25 CSS Formatter Format CSS or minify it.developer26 JavaScript Formatter Format with Prettier or minify with Terser.developer27 SQL Formatter Lay out a SQL statement.developer28 Regex Tester Highlights matches and capture groups.developer29 HTML Playground HTML, CSS and JS in a sandboxed frame.developer30 CSS Gradient Generator Build a linear gradient and copy the CSS.developer31 Box Shadow Generator Tune a shadow and copy the declaration.developer32 Flexbox Playground Direction, wrap, alignment and gap.developer33 Grid Generator Columns, rows and gap as CSS Grid.developer34 Responsive Breakpoint Preview See HTML at phone, tablet and desktop widths.developer35 UUID Generator Version 4 UUIDs from the browser CSPRNG.developer36 Lorem Ipsum Generator Paragraphs of placeholder text.developer37 Hash Generator SHA-1, SHA-256, SHA-384 and SHA-512.developer38 Cron Expression Explainer Explain a five-field cron expression.developer39 IP Address Information Classify an address you type. No network scan.developer40 Date Formatter Format a date with a token pattern.developer41 Timezone Converter Convert a civil time between IANA zones.developer42 Git Command Reference A short field guide to everyday Git.developer43 HTTP Status Codes Look up a status code.developer44 MIME Type Lookup Find a content type by extension or name.developer45 Common Regex Patterns Starting points for email, URL, numbers and more.developer46 HTML Entity Reference Named characters and their codes.developer47 CSS Unit Converter px, rem, em, pt and percent.developer48 Case Converter Upper, lower, title, camel, snake and kebab.text49 Remove Duplicate Lines Keep the first copy of each line.text50 Sort Lines Sort lines A–Z or Z–A.text51 Text Diff Line-by-line additions and removals.text52 Markdown Preview Write Markdown and see sanitized HTML.text53 Slug Generator URL slugs, including Cyrillic and Armenian.text54 Whitespace Cleaner Trailing spaces, repeated blanks and non-breaking spaces.text55 JSON to YAML Turn a JSON document into YAML.developer56 YAML to JSON Turn YAML into formatted JSON.developer57 Sort JSON Keys Sort object keys recursively.developer58 Subnet Calculator Network, mask, hosts and broadcast from CIDR.developer59 Chmod Calculator Octal modes such as 755 to rwx.developer60 ROT13 Rotate letters by 13 places.developer61 Morse Code Text to Morse and back.developer62 Data URL Encode text as a base64 data URL.developer63 Line Endings Convert between LF and CRLF.developer64 Basic Auth Decoder Read user and password from a Basic header.developer65 .env Parser Turn KEY=value lines into JSON.developer66 Random String A CSPRNG string of the length you set.developer67 Strip HTML Remove tags and return the text.developer68 TSV to JSON Tab-separated rows become objects.developer69 Password Strength A local entropy estimate.developer70 Aspect Ratio Simplify a pixel width and height.developer71 API Request Sends your requestSend GET, POST, PUT, PATCH or DELETE from this browser.developer72 Semver Compare Compare two semantic versions, including prerelease.developer73 Semver Bump Raise major, minor or patch.developer74 Query Builder Turn key=value lines into a query string.developer75 Human Bytes Show a byte count in KB, MB or GB.developer76 Duration Format Seconds as hours, minutes and seconds.developer77 Path Parts Directory, name and extension.developer78 SQL IN Clause Quote lines as an SQL IN list.developer79 Markdown Table CSV rows become a Markdown table.developer80 Meta Tags Title and description tags for a page.developer81 Robots.txt Builder Allow and disallow rules for one user agent.developer82 Base32 Encode and decode Base32 text.developer83 Punycode International domain labels to and from ASCII.developer84 IPv4 Integer An IPv4 address as an unsigned integer.developer85 MAC Formatter Normalize a MAC address to colon groups.developer86 JSON Keys List every object key path.developer87 UTF-8 Length Byte length, not character length.developer88 Hex Dump UTF-8 bytes in rows of 16.developer89 CSV Delimiter Replace one delimiter with another.developer90 Lines to JSON A JSON array of the non-empty lines.developer91 Luhn Check Checksum for a card-like number. It does not contact a bank.developer92 IBAN Check Mod-97 check of an IBAN. It does not look the account up.developer93 Email Shape A practical shape check, not a mailbox lookup.developer94 Passphrase Random English words from a fixed local list.developer95 ULID Generator Sortable identifiers from time and the browser CSPRNG.developer96 CSS clamp() A clamp() declaration from three lengths.developer97 Type Scale A modular type scale in pixels.developer98 Color Shades Five lighter and darker steps of one hex color.developer99 Complementary Color The opposite hue of a hex color.developer100 Spacing Scale A spacing ramp from a base and a ratio.developer101 SVG Placeholder A small SVG with a label. No image host.developer102 Redirect Rule An Apache Redirect line for 301 or 302.developer103 HTML Table CSV rows become table cells.developer104 Letter Avatar An SVG avatar from one letter.developer105 CSS Radius A border-radius declaration.developer106 CSS Filter Blur and brightness as a filter declaration.developer107 JSON Size UTF-8 byte size of the text you pasted.developer108 Data Rate Bytes over seconds, shown in human units.developer109 Strip Comments Remove //, # and /* */ comments from text.developer

About

01

Safe for tokens and keys

JWTs, API responses and secrets are processed on your device and never sent to a server. Sensitive tools are also kept out of account history unless you allow it.

02

Chain tools into a flow

Text tools can be linked in Tools Flow: for example, decode Base64, pretty-print the JSON and then minify it, all in one pass.

FAQ

Frequently asked questions

Is it safe to paste a JWT or an API key here?

Yes. Decoding and hashing happen in your browser. Nothing you paste is uploaded or logged.

Which formats are supported?

JSON, YAML, XML, CSV, Base64, URL encoding, HTML entities, SHA-256 and SHA-512 hashes, UUIDs, cron expressions, regular expressions and more.

Can I use these tools offline?

Once the site has loaded, most tools keep working without a connection because they run locally.