DevPrism

Hash a string with bcrypt at a work factor you choose, or test a string against an existing bcrypt hash.

Run text through MD5, SHA-1, SHA-256, SHA-3 and other digests, with each result shown in several encodings at once.

Compute an HMAC signature from a message and secret key using the hash function of your choice.

Split a JSON Web Token into its header, payload, and signature and read the decoded claims.

Estimate how long a password would take to crack and see which choices are weakening it.

Inspect the digital signatures embedded in a PDF and check whether the file changed after it was signed.

Generate a fresh RSA public and private key pair in PEM format at the key size you pick.

Mask the middle of a secret, IBAN, or token so it can be shared and recognised without exposing the whole value.

Encrypt or decrypt a message with a passphrase using AES, TripleDES, Rabbit, or RC4.

Build a random token from the character sets you enable — lowercase, uppercase, digits, symbols — at any length.

Create ULIDs, the time-sortable unique identifier, one at a time or in bulk, as plain text or JSON.

Create RFC 4122 UUIDs (v1, v3, v4, v5) singly or in bulk, in several output formats.

Toggle read, write, and execute bits for owner, group, and others to get the matching octal mode and chmod command.

Assemble a cron expression from plain-language options and read back exactly when it will run.

Paste a docker run command and get the equivalent docker-compose service definition.

Open a Minecraft plugin or mod .jar in the browser to browse its files, preview them, and extract individual entries.

Pick a random TCP port from the ephemeral range, clear of the well-known ports below 1024.

Try a regular expression against sample text and watch every match and capture group highlight as you type.

Reformat a SQL query with clean indentation and consistent keyword casing across common dialects.

A searchable quick reference for .gitignore pattern syntax, common entries per stack, and related git commands.

A searchable quick reference for ANSI/VT100 escape codes — terminal colors, text styles, cursor movement, and clearing.

A searchable quick reference for Bash — redirection, variable expansion, globs, tests, control flow, and process management.

A searchable quick reference for Conventional Commits message types and Semantic Versioning (MAJOR.MINOR.PATCH) rules.

A searchable quick reference for CSS color formats and functions — hex, rgb/hsl/oklch, keywords, gradients, and filters.

A searchable quick reference for CSS selectors — combinators, attribute selectors, pseudo-classes/elements, and specificity.

A searchable quick reference for curl — methods, request bodies, headers, auth, output options, and redirects.

A searchable quick reference mapping date/time format tokens across strftime, date-fns/Moment, and Go's reference layout.

A searchable quick reference for the Docker CLI — running and managing containers, images, Compose, volumes, cleanup, and Dockerfile instructions.

A searchable quick reference for the find command — matching by name, type, size, and time, then acting on the results.

A searchable quick reference for CSS Flexbox and Grid — container and item properties, plus common layout recipes.

A searchable quick reference for Git — everyday commands, branching, undoing mistakes, stashing, remotes, and history search.

A searchable quick reference for glob syntax across the shell, .gitignore-style files, and JS tooling (picomatch/fast-glob).

A searchable quick reference for Go — variables, slices & maps, structs & interfaces, goroutines/channels, and errors.

A searchable quick reference for grep and ripgrep (rg) — matching, context lines, and restricting search by file type.

A searchable quick reference for HTTP methods, safe/idempotent/cacheable semantics, status code ranges, and common headers.

A searchable quick reference for modern JavaScript — array, string, object, and async/Promise built-ins.

A searchable quick reference for jq — filters, transforms, reductions, and string/regex helpers for JSON on the command line.

A searchable quick reference for kubectl — contexts, get/describe, logs & exec, applying manifests, and debugging.

A searchable quick reference for GNU Make — rules, variables, automatic variables, functions, and CLI flags.

A searchable quick reference for Markdown — text formatting, lists, links, and GitHub Flavored Markdown extensions.

A searchable quick reference for Python — slicing, comprehensions, f-strings, functions, control flow, and type hints.

A quick reference for JavaScript regular-expression syntax: tokens, character classes, groups, flags, and lookarounds.

A searchable quick reference for Rust — ownership & borrowing, pattern matching, iterators, traits, and Cargo.

A searchable quick reference for sed and awk — substitution, line selection, fields, and quick filters/aggregates.

A searchable quick reference for SQL — queries, joins, aggregation, window functions, DDL, and CTEs.

A searchable quick reference for SSH, SCP, and rsync — connecting, keys, port forwarding, file transfer, and ~/.ssh/config.

A searchable quick reference for systemctl and journalctl — controlling services, inspecting units, and reading logs.

A searchable quick reference for well-known and commonly-used TCP/UDP ports — web, mail, infra, databases, and dev servers.

A searchable quick reference for tmux — sessions, windows, panes, copy mode, and config reloading.

A searchable quick reference for TypeScript — basic types, interfaces, generics, utility types, and conditional/mapped types.

A searchable quick reference for Vim/Neovim — modes, motions, editing, search & replace, windows, registers, and macros.

Compare two JSON documents and see added, removed, and changed values highlighted side by side.

Strip whitespace and line breaks from JSON to produce the smallest valid output.

Re-indent JSON with consistent spacing so it is easy to scan.

Flatten an array of JSON objects into CSV, working out the column headers for you.

Re-indent an XML document with consistent spacing and line breaks.

Check whether an XML document is well-formed and point to the first place parsing fails.

Render an XML document as a nested HTML table and copy the generated markup.

Convert an XML document into JSON, keeping attributes as @-prefixed keys.

Evaluate an XPath expression against an XML document and inspect the nodes it selects.

Apply an XSLT stylesheet to an XML document and see the transformed result.

Flatten nested YAML into dotted keys, or expand dotted keys back into nested structure.

Deep-merge two or more YAML documents, with each one overriding the values before it.

Re-dump a YAML document with consistent indentation, optionally sorting the keys.

Convert YAML into JSON, including multi-document streams.

Convert a YAML mapping into equivalent TOML.

See an IPv4 address written as decimal, hexadecimal, binary, and its IPv6-mapped form.

Enter the first and last address of a range and get the smallest CIDR block that covers it.

Break an IPv4 CIDR block down into its network and broadcast address, usable host range, mask, and size.

Roll a random IPv6 unique local address prefix (fd00::/8) for private networks, following RFC 4193.

Generate one or many random MAC addresses with a fixed prefix, case, and separator of your choosing.

Look up the hardware vendor registered to a MAC address or OUI prefix.

Combine a username and password into the Base64 value for an HTTP Basic Authorization header.

Read back what the browser exposes about your screen, viewport, platform, and capabilities.

Reduce an email address to a canonical form — lowercasing, dropping dots and +tags — so duplicates line up.

Convert reserved characters like <, >, and & into HTML entities, or turn entities back into characters.

Edit rich text visually and get the matching HTML source updated as you type.

Browse every HTTP status code with its short name and what it signals.

Press any key to see its JavaScript key, code, keyCode, location, and active modifiers.

Look up the MIME type for a file extension, or the extensions tied to a MIME type.

Fill in a short form to generate the Open Graph and Twitter Card meta tags for a page.

Recover the original link wrapped inside an Outlook SafeLinks URL.

Turn a phrase into a lowercase, hyphenated slug that is safe for URLs, filenames, and IDs.

Percent-encode text for safe use in a URL, or decode a percent-encoded string back to plain text.

Break a URL into its parts: scheme, host, port, path, query parameters, and credentials.

Follow every hop in a URL's redirect chain and see the status code and target at each step.

Pull the browser, engine, operating system, CPU, and device out of a user-agent string.

Turn a line of text into large ASCII-art lettering, choosing from a range of FIGlet fonts.

Search and copy emoji along with their name, Unicode codepoints, and shortcode.

Generate filler paragraphs, sentences, or words of lorem ipsum for mockups and layout work.

Shorten words to numeronyms such as i18n or a11y, and expand them back again.

Compare two blocks of text and highlight what changed — by line, by word, or by character.

Count characters, words, lines, and byte size for any block of text as you type.

Calculate the monthly payment on a loan and see the full principal/interest schedule.

Calculate Body Mass Index from your weight and height, in metric or imperial units.

Calculate the great-circle distance and initial bearing between two latitude/longitude points.

Type a mathematical expression and get the result, with support for functions like sqrt, sin, and log.

Decode a resistor's color bands into its resistance and tolerance, or the reverse — type a value to get the bands.

Solve for time, pace, or distance from the other two, with quick presets for common race distances.

Work out the tip and total on a bill, and split it evenly between any number of people.

Generate 1D and 2D barcodes — Code 128, EAN, UPC, ITF, Data Matrix, PDF417, Aztec and more — and save them as PNG or SVG.

Read a barcode or QR code from an uploaded image or a live camera feed.

Build a SEPA credit-transfer QR code (GiroCode / EPC069-12) that a banking app can scan to prefill a payment.

Check the GS1 check digit of a GTIN-8, GTIN-12, GTIN-13 (EAN-13), or GTIN-14 barcode number.

Read a QR code from an image or your camera and work out what kind of content it carries.

Turn a URL or any text into a QR code, set the error-correction level, and download it.

Enter contact details and get a vCard QR code that scans straight into a phone’s address book.

Create a QR code that joins a phone to your Wi-Fi network in one scan.

Build a placeholder image at any size — pick colours, a label, and a pattern, then export it as SVG, PNG, JPEG, or WebP with ready-made HTML, CSS, and Markdown snippets.

Generate a BIP39 recovery phrase from random entropy, or paste a phrase to recover the entropy behind it. Multiple wordlists supported.

Generate live TOTP and HOTP codes from a Base32 secret, with a scannable QR code for authenticator apps.