Developer & Data Tools — Encoders, JSON, Crypto, Regex & More

Scan a QR code from any image and decode it to text — free, online, runs entirely in your browser.

Render a Mermaid diagram as a scalable SVG — paste the code or upload an .mmd file.

Render a Mermaid diagram as a high-resolution PNG — paste the code or upload an .mmd file.

Render a Mermaid diagram as a JPG image — paste the code or upload an .mmd file.

Render a Mermaid diagram as a single-page PDF — paste the code or upload an .mmd file.

Generate a QR code from any text, URL or contact data — pick error correction and scale, get a PNG.

Convert any file's bytes to a hex dump (with ASCII sidecar), plain hex, C array or comma-separated bytes.

Parse a hex dump or hex string back into a binary file — strips offsets, ASCII columns, prefixes and separators automatically.

Generate a Wi-Fi QR code as a PNG — scanning it auto-joins the network. Supports WPA / WEP / open networks and hidden SSIDs.

Generate a QR code that contains a digital business card (vCard) — scanning it lets the phone save the contact in one tap.

Generate a 1D barcode (CODE128, EAN-13, UPC-A, CODE39, ITF-14, MSI, codabar, pharmacode) as a downloadable PNG.

Encode any text to Base64 (and URL-safe Base64) — runs locally in your browser, free and online.

Decode Base64 or URL-safe Base64 strings back to UTF-8 text — runs locally in your browser.

Percent-encode text for safe use in URLs — supports both encodeURIComponent and encodeURI.

Decode percent-encoded URL text back to its readable form — supports decodeURIComponent and decodeURI.

Decode a JSON Web Token to inspect its header and payload — runs locally, your token never leaves the browser.

Compute MD5, SHA-1, SHA-256, SHA-384 or SHA-512 of any text — runs locally in your browser.

Generate cryptographically random UUIDs (v4) or time-ordered UUIDs (v7) — runs locally in your browser.

Pretty-print or minify any JSON document — validates structure and reports parse errors with position.

Convert any string to lowercase, UPPERCASE, Title Case, camelCase, snake_case, kebab-case and more — all at once.

Generate placeholder lorem ipsum text — by paragraph, sentence or word count.

Encode text to HTML entities — escape <, >, &, " and ' (and optionally everything non-ASCII).

Decode HTML entities back to plain text — handles numeric (&#NNN; / &#xNNN;) and the common named entities.

Decode a hex string back to UTF-8 text — accepts 0x prefixes, spaces, and any case.

Encode UTF-8 text as a hex string — lowercase, uppercase, space-separated or 0x-prefixed.

Decode 8-bit binary (groups of 0/1) back to UTF-8 text — space- or comma-separated.

Encode UTF-8 text as 8-bit binary groups — choose space, comma or no separator.

Apply the ROT13 substitution cipher — letters shift by 13, applying twice returns the original.

Encrypt or decrypt text with the classic Caesar shift cipher — choose any shift from -25 to 25.

Reverse text by character or by word — Unicode-aware so emoji and combining marks stay intact.

Sort lines alphabetically or numerically, ascending or descending, case-sensitive or not.

Remove duplicate lines from a list — case-sensitive or not, preserve original order or not.

Count characters, words, lines, sentences, paragraphs and estimate reading time.

Convert any text to a clean, URL-safe slug — strips diacritics and replaces non-alphanumerics.

Generate cryptographically random passwords — choose length, character classes, and exclude lookalikes.

Estimate password entropy and crack time — checked entirely locally, nothing uploaded.

Generate batches of random strings — pick charset, length and count, all sourced from crypto.getRandomValues.

Generate uniform random integers in a range — uses crypto.getRandomValues for true uniformity.

Infer TypeScript interfaces from any JSON payload — nested objects get their own named interface.

Test a JavaScript regular expression against sample text — see matches, groups, and a replacement preview.

Convert between Unix timestamps and human-readable dates — auto-detects seconds vs milliseconds.

Explain a cron expression in plain English and show the next firing times.

Convert a hexadecimal number to decimal — also shows binary and octal. Handles arbitrary-size integers via BigInt.

Convert a decimal integer to hexadecimal — also shows binary and octal. Uppercase output with optional 0x prefix.

Convert a binary number to decimal — also shows hex and octal. Spaces and underscores ignored.

Convert a decimal integer to binary — also shows hex and octal. Group bits by 4 or 8 for readability.

Convert a hexadecimal number to binary — each hex digit becomes 4 bits, padded. Also shows decimal.

Convert a binary number to hexadecimal — input is padded to a multiple of 4 bits. Also shows decimal.

Convert a number between any two bases from 2 to 36 — also shows the value in binary, octal, decimal and hex.

Encode each character as its Unicode code point in decimal — space-, comma- or newline-separated output.

Decode a list of decimal Unicode code points back to text — any separator (space, comma, newline) accepted.

Convert text into Unicode escape sequences — U+XXXX, \uXXXX, &#XXXX; or %uXXXX. Hex digits are uppercase.

Decode mixed Unicode escapes (U+XXXX, \uXXXX, \u{XXXXX}, \xHH, &#XXXX;, %uXXXX) back to plain text.

Encode UTF-8 text to RFC 4648 Base32 — alphabet A-Z and 2-7, with = padding. Useful for TOTP secrets and DNS-safe identifiers.

Decode RFC 4648 Base32 (A-Z, 2-7) back to UTF-8 text — case-insensitive, padding optional.

Encode text to Quoted-Printable (RFC 2045) — for email bodies. Non-ASCII bytes become =XX, lines soft-wrap at 76 columns.

Decode Quoted-Printable (RFC 2045) text back to UTF-8 — handles =XX escapes and soft line breaks (=\r\n).

Encode text into international Morse code (ITU-R M.1677-1) — letters, digits and common punctuation supported.

Decode international Morse code (ITU) back to plain text — letters separated by spaces, words by /.

Convert text into l33t sp34k — three intensity levels: mild (a→4, e→3, i→1, o→0, s→5, t→7), strong, and maximum.

Compute HMAC-SHA1, HMAC-SHA256, HMAC-SHA384 or HMAC-SHA512 of a message under a secret key — output in hex and base64.

Generate a bcrypt hash from a password, or verify a password against an existing bcrypt hash — adjustable cost factor.

Generate an RSA private/public key pair as PEM (2048, 3072 or 4096-bit) and a SHA-256 fingerprint of the public key.

Generate a BIP39 mnemonic seed phrase (12/15/18/21/24 words) and the corresponding entropy + seed — or convert an existing mnemonic to its seed.

Generate ULIDs — Universally Unique Lexicographically Sortable Identifiers — that double as a sortable timestamp prefix.

Build a cron expression from fields or pick a preset — get the expression plus a human-readable description.

Build URLs for placeholder images — picsum.photos, placeholder.com, dummyimage.com and ui-avatars — with the matching HTML/Markdown/BBCode snippets.

Generate realistic-looking fake people data — names, emails, phones, addresses — for seeding databases, designing UIs and writing tests.

Compare two JSON documents and show added, removed and changed fields as a path-based tree.

Deep-merge two JSON documents — choose how to handle conflicting keys and arrays.

Generate an RFC 6902 JSON Patch describing the changes needed to turn one JSON document into another.

Apply an RFC 6902 JSON Patch to a JSON document — supports add, remove, replace, move, copy and test.

Infer a JSON Schema (Draft-07) from any JSON document — nested objects and array element types are inferred recursively.

Flatten a nested JSON document to a single-level object with dot, underscore or bracket paths.

Expand a flat dot/bracket-keyed object back into nested JSON — numeric keys become array indices.

Sort the keys of a JSON object alphabetically — recursively, case-insensitively, or with numeric awareness.

Query a JSON document with a JSONPath expression — supports $, ., [n], [*], ..key and [?(@.field op value)] filters.

Generate Go structs with json tags from any JSON payload — nested objects become separate named types.

Generate Python @dataclass, pydantic BaseModel or TypedDict definitions from any JSON payload.

Generate Rust structs with serde derives from any JSON payload — fields auto-renamed to snake_case.

Generate C# classes from JSON with typed properties for nested objects and arrays.

Generate Kotlin data classes from JSON for Android, Ktor and API clients.

Count the words in any text — plus characters, lines, paragraphs and estimated reading time. Free, online, no signup.

Count characters in any text — with and without spaces — plus words, lines and paragraphs. Free, online, runs in your browser.

Compare two texts side by side and highlight added, removed and unchanged lines, words or characters.

Paste tab-separated values and get a clean GitHub-flavored Markdown table — instantly.

Convert text to NATO phonetic alphabet (Alpha, Bravo, Charlie…) and back — free, in your browser.

Analyze an IP address — validate format, identify type (private/public/loopback), class, and binary representation.

Validate email addresses instantly — check format, detect typos, spot disposable providers. Free online tool, no signup.

Convert standard Markdown to Slack mrkdwn format — bold, italic, links, code blocks, lists. Free, instant, in-browser.

Calculate the CRC32 checksum of any text — hex and decimal output. Free, instant, runs in your browser.

Strip HTML tags and convert to clean plain text — handles entities, scripts, styles, links. Free, instant, in-browser.

Convert text to ASCII art block letters — A-Z, 0-9, punctuation. Free, instant, in-browser.

Build campaign URLs with UTM source, medium, campaign, term and content parameters.

Break a URL into its components — protocol, host, port, path, query parameters, hash — with each query param listed individually.

Parse a browser User-Agent string into structured browser/engine/OS/device fields.

Look up any HTTP status code — title, category, RFC explanation, and the situations it's actually used for.

Look up the MIME type for a file extension, or the canonical extensions for a MIME type — covering 100+ common types.

Calculate network/broadcast addresses, host range, mask, wildcard mask, host counts, and IP class from a CIDR.

Minify CSS — strip whitespace, comments and unused syntax to ship smaller stylesheets.

Pretty-print CSS — choose 2-space, 4-space or tab indentation for readable stylesheets.

Minify HTML — collapse whitespace, drop comments and optionally compress inline JS and CSS.

Pretty-print HTML — readable indentation with nested tags on their own lines.

Minify JavaScript with Terser — compress, mangle and ship the smallest possible bundle.

Pretty-print JavaScript — consistent indentation and one statement per line for readable code.

Format SQL queries for every major dialect — Postgres, MySQL, SQLite, BigQuery, Snowflake and more.

Pretty-print XML documents — indent nested tags with 2 or 4 spaces for readable markup.

Reformat YAML — normalize indentation, line wrapping and quoting for tidy config files.

Validate CSV data — check column consistency, count rows and surface parse errors.

Convert Apache .htaccess rewrite rules and directives to nginx configuration — free, in your browser.

Interactive regex reference — anchors, quantifiers, groups, character classes, lookaround, and flags with examples.

Validate JSON and see errors with line numbers — plus auto-format/beautify. Free, instant, in-browser.

Convert between numeric (755) and symbolic (rwxr-xr-x) Unix file permissions. Free, instant, in-browser.

Generate HTML meta tags for SEO, Open Graph, and Twitter Cards. Free, instant, copy-paste ready.

Build a Content-Security-Policy header interactively — select policies for each directive and get the full header string.

Test whether a URL path is allowed or blocked by robots.txt rules for a specific crawler.

Generate hreflang alternate link tags from language codes and localized URLs.

Find the numeric Instagram user ID for a public profile URL or username.

Find the numeric Facebook profile or page ID from a public URL, username, or ID link.

Validate a card number with the Luhn (mod-10) algorithm — runs locally in your browser.

Generate Luhn-valid test card numbers (Visa, Mastercard, Amex, Discover, JCB, Diners) — for development only.

Identify the card scheme (Visa, Mastercard, Amex, Discover, JCB, Diners, UnionPay) from a PAN.

Look up a card BIN (Bank Identification Number) to identify scheme, issuer, country and type.

Decode EMV / ISO 7816 BER-TLV hex into a labelled tree of tags, lengths and values.

Search the EMV / ISO 7816 tag dictionary by hex tag or by name fragment.

Decode an ISO 7813 Track 1 magstripe string into PAN, cardholder name, expiry and service code.

Decode an ISO 7813 Track 2 magstripe string into PAN, expiry, service code and discretionary data.

Generate an ISO 9564 PIN block (formats 0, 1 and 3) from a PIN and PAN — runs locally in your browser.

Compute the Key Check Value (KCV) of a single, double or triple length DES key by encrypting 8 bytes of zeros.

Look up a currency by ISO 4217 code (alpha or numeric) or by name fragment.

Look up a country by ISO 3166-1 alpha-2, alpha-3, numeric code, or by name fragment.

Look up an ISO 18245 Merchant Category Code by 4-digit code or by name fragment.

Validate an IBAN — checks the country format, length and ISO 13616 MOD-97 checksum.

Validate a SWIFT/BIC code format and break it down into bank, country, location and branch fields.

Look up a language by ISO 639-1 alpha-2, ISO 639-2/3 alpha-3, or by name fragment.

Format a card number for display — brand-aware grouping plus a masked version safe to show in receipts.

Compute the ISO 8583 field 52 encrypted PIN block from a PIN, PAN, BDK and KSN — full TDES DUKPT key derivation.