Tool Usage Guides

Practical, tool-first walkthroughs for getting real work done in your browser. Each guide links straight to the utility it covers — no theory, no filler.

Decode and verify a JWT locally (no server, no leaking secrets)

Inspect a JSON Web Token header and payload in your browser — without pasting a live token into a third-party site.

Pretty-print and validate JSON before you ship it

Catch a missing comma or trailing brace before it breaks a deploy — format and validate JSON right in your browser.

Convert CSV to JSON (and back) entirely in the browser

Turn a pasted spreadsheet into clean JSON objects, or flatten JSON for a table — with no script and no upload.

Test a regex against live sample text before deploying

Catch a regex that matches too much or too little — validate it against real input before it ships to production.

Generate UUIDs and hashes locally for prototypes

Spin up RFC-4122 UUIDs and MD5/SHA hashes on-device for stubs, fixtures, and quick integrity checks — no backend needed.

Encrypt and decrypt text with AES-256-GCM (no server, no upload)

Share a secret or lock down a note with AES-256-GCM and a passphrase — everything runs in your browser.

Sign messages with HMAC-SHA to prove they were not tampered

Generate an HMAC-SHA256/384/512 tag from a secret key so a receiver can verify integrity and authenticity.

Obfuscate text with a Caesar or ROT13 shift

Shift letters to hide a spoiler or teach cipher basics — a toy cipher, not real security.

Encode binary as Base32 or Base58 without ambiguous characters

Pick an alphabet that survives human copying — Base32 for filenames, Base58 for crypto-style identifiers.

Translate text to and from Morse code

Convert a message into International Morse code or decode a Morse string back to text.

Escape and unescape strings for JS, JSON, HTML, SQL, or CSV

Make dynamic strings safe to embed — or recover them — across five common formats.

Count characters, words, lines, and UTF-8 bytes

Know exactly how long your text is — including the byte count that limits often actually enforce.

Sort, dedupe, trim, and clean lists of lines

Turn a messy pasted block into an ordered, duplicate-free list in a couple of clicks.

Turn a title into a URL-safe slug

Convert a heading into a clean permalink — lowercase, hyphenated, and free of characters that break links.

Convert Roman numerals to numbers and back

Read a clock face, copyright year, or outline marker — convert between Roman numerals and 1–3999.

Measure string similarity with Levenshtein distance

Quantify how alike two strings are — for fuzzy matching, typo detection, and deduplication.

Pretty-print and validate XML

Indent a messy XML document and surface well-formedness errors before it reaches a parser.

Extract nested values from JSON with a path

Pull one field out of a large JSON payload using simple dot-path notation.

Convert colors between HEX, RGB, and HSL

Move a color between the notations designers and developers actually use.

Break any URL into its parts

Split a URL into protocol, host, path, query, and fragment to debug links and redirects.

Calculate IP ranges from a CIDR block

Turn 192.168.0.0/24 into its network, broadcast, and usable host counts.

Look up MIME types by file extension

Find the correct Content-Type for an extension, or identify an extension from a MIME type.

Parse and build URL query strings

Split a query into key/value pairs, sort them, or assemble a clean one from scratch.

Generate strong, random passwords

Create high-entropy passwords with the character rules you need — locally, with a crypto random source.

Generate Lorem Ipsum placeholder text

Fill a mockup with realistic placeholder copy — by paragraphs, sentences, or words.

Convert a time across world time zones

Translate a date and time from one zone to another, with the Unix epoch for unambiguous storage.

Debug an API request in the browser (including CORS)

Build a real request, watch the status and timing, and see exactly why a call fails — without standing up a backend.

Read an HTTP status code and pick the fix

Turn a bare status number into meaning and the usual remedy — 2xx, 3xx, 4xx, or 5xx.

Fix CORS errors without guessing

Paste the browser console error, get the likely cause, then generate the exact server headers to fix it.

Measure API latency against a budget

Take a measured response time, compare it to your latency budget, and know where to look next.

Beautify minified JavaScript in the browser

Re-indent a collapsed script for reading or debugging — no upload, no dependency.

Tidy messy HTML and CSS markup

Re-indent tangled HTML or CSS so you can read and edit it — entirely in the browser.

Lint YAML and INI config before deploy

Catch tabs, trailing whitespace, and malformed key/value lines before they break a deploy.

Understand cache headers without guessing

Paste response headers and learn whether a resource is fresh, revalidated, or never cached.

Generate CORS headers for Nginx or Apache

Turn your allowed origin, methods, and headers into copy-ready server config and a matching fetch().