# jigg.dev

> Tools for small jobs by Caleb Terry. Quick utilities that run entirely in your browser.

Every tool runs in the visitor's browser: nothing typed or uploaded is sent to a server or stored. Most tools keep their state in the URL, so a link reopens the same result.

In browsers with WebMCP (`navigator.modelContext`), every page registers the agent tools listed below, so an assistant can call them directly instead of driving the page.

## Tools

- [Font previewer](https://tools.jigg.dev/tools/font-previewer): Try Google Fonts with your own text, pair a heading font with a body font, and copy the link and CSS.
- [Big text](https://tools.jigg.dev/tools/big-text): Type a message and show it as large as the screen allows, fullscreen and upside down for across the counter.
- [Chord finder](https://tools.jigg.dev/tools/chord-finder): Pick a chord and see the easiest ways to play it on guitar or ukulele, with diagrams you can hear.
- [Reaction time test](https://tools.jigg.dev/tools/reaction-time): Wait for green, tap as fast as you can, and get your median over five tries; your best stays in this browser.
- [SSH key generator](https://tools.jigg.dev/tools/ssh-keygen): Make an Ed25519 or RSA key pair in OpenSSH format, with its fingerprint, without the key leaving your browser.
- [CSV viewer](https://tools.jigg.dev/tools/csv-viewer): Open a big CSV to sort, filter and count by column, with sums and averages; nothing is uploaded.
- [JSON query](https://tools.jigg.dev/tools/json-query): Run a jq filter or a JSONPath against pasted JSON and see the result as you type.
- [SVG optimizer](https://tools.jigg.dev/tools/svg-optimizer): Shrink an SVG, compare before and after, and copy it as a file, data URI, CSS or React component.
- [Type scale generator](https://tools.jigg.dev/tools/type-scale): Pick a body size and ratio for small and large screens and get fluid clamp() font sizes from small print to h1.
- [Certificate decoder](https://tools.jigg.dev/tools/certificate-decoder): Paste a PEM certificate, chain or CSR to see its names, issuer, key, expiry and fingerprints, and check a hostname against it.
- [URL inspector](https://tools.jigg.dev/tools/url-inspector): Split a link into its parts, edit the query string as a table, strip tracking parameters and copy the rebuilt URL.
- [Table converter](https://tools.jigg.dev/tools/table-converter): Paste cells from a spreadsheet, CSV or a Markdown table and get Markdown, HTML, CSV or a plain-text grid.
- [Loan calculator](https://tools.jigg.dev/tools/loan-calculator): Monthly payment, total interest and a full amortization schedule, with what extra payments save.
- [Team picker](https://tools.jigg.dev/tools/team-picker): Split a list of names into fair random teams, balanced by rating if you like, with captains picked too.
- [Stair stringer calculator](https://tools.jigg.dev/tools/stair-stringer): Riser height, step count, total run and stringer length from the total rise, checked against common code limits.
- [Material estimator](https://tools.jigg.dev/tools/material-estimator): How much paint, drywall, flooring, tile or bagged concrete a room or slab takes, with a waste allowance.
- [Chmod calculator](https://tools.jigg.dev/tools/chmod-calculator): Tick read, write and execute to get the octal and symbolic mode, or paste 755, -rwxr-xr-x or u+x to decode it.
- [Semver checker](https://tools.jigg.dev/tools/semver-checker): Check which versions satisfy a range like ^1.4 or ~2.0.3, and see what the range means in plain comparators.
- [Interval timer](https://tools.jigg.dev/tools/interval-timer): Pomodoro, Tabata or your own work and rest rounds, with countdown beeps and the screen kept awake.
- [Board foot calculator](https://tools.jigg.dev/tools/board-feet): Add up lumber by the board foot from thickness, width and length, with a waste allowance and a price for the total.
- [Miter & angle calculator](https://tools.jigg.dev/tools/miter-angle): Miter angles for frames and polygons, miter and bevel for splayed boxes, and crown molding settings for any corner.
- [Sun times](https://tools.jigg.dev/tools/sun-times): Sunrise, sunset, golden hour, blue hour and twilight for any city or your location, on any date.
- [JSON to types](https://tools.jigg.dev/tools/json-to-types): Paste sample JSON and get TypeScript interfaces or a zod schema, with optional and nullable fields worked out.
- [Text cleaner](https://tools.jigg.dev/tools/text-cleaner): Fix pasted text in one go: smart quotes, odd spaces, extra blank lines, duplicates, sorting and case.
- [Tape measure calculator](https://tools.jigg.dev/tools/tape-measure): Add, subtract and divide feet, inches and fractions like 3' 5 5/8", rounded to the nearest 1/16 or finer.
- [Cut list optimizer](https://tools.jigg.dev/tools/cut-list): Lay out the parts you need on the boards or sheets you have, with saw kerf, and see the offcuts and waste.
- [IP list tools](https://tools.jigg.dev/tools/ip-list): Merge, dedupe and sort a list of IPs, CIDRs and ranges, subtract another list, and check whether an address is on it.
- [Metronome](https://tools.jigg.dev/tools/metronome): Keep time with accents, subdivisions, a tempo trainer that speeds up as you go, and silent bars to test yourself.
- [Image cropper](https://tools.jigg.dev/tools/image-cropper): Crop a photo to an exact size for Instagram, YouTube, a profile picture or any ratio, then download it.
- [Screenshot framer](https://tools.jigg.dev/tools/screenshot-framer): Drop a screenshot and put it on a gradient with padding, a shadow and a browser or phone frame, ready to post.
- [Guitar & ukulele tuner](https://tools.jigg.dev/tools/tuner): Tune a guitar, ukulele or bass with your microphone: see the note and how sharp or flat it is, with a metronome.
- [PDF merge & split](https://tools.jigg.dev/tools/pdf-merge-split): Combine PDFs, reorder, rotate or delete pages, or pull pages out into a new file; nothing is uploaded.
- [Wheel spinner](https://tools.jigg.dev/tools/wheel-spinner): Paste a list of names and spin the wheel to pick one, with a link that keeps the list.
- [Favicon maker](https://tools.jigg.dev/tools/favicon-maker): Turn one image into favicon.ico, an Apple touch icon and app icons, with the HTML to add them, in one zip.
- [Barcode maker](https://tools.jigg.dev/tools/barcode-maker): Make EAN-13, UPC-A and Code 128 barcodes and download them as PNG or SVG.
- [Typing speed test](https://tools.jigg.dev/tools/typing-test): Measure your words per minute and accuracy, and see which keys you miss most.
- [Fake data generator](https://tools.jigg.dev/tools/fake-data): Make realistic test users, addresses and orders as JSON or CSV, the same every time from a seed.
- [Paste link](https://tools.jigg.dev/tools/paste-link): Turn text into a link that carries it, compressed and optionally locked with a password; nothing is stored anywhere.
- [Photo privacy check](https://tools.jigg.dev/tools/photo-metadata): See the hidden metadata in a photo, like GPS location, camera and date, then download a clean copy.
- [Mic & camera check](https://tools.jigg.dev/tools/mic-camera-check): Test your webcam, microphone level and speakers before a call, and record a short clip to hear yourself.
- [Social card maker](https://tools.jigg.dev/tools/social-card): Design a 1200×630 share image with a title, colors and your logo, then download it as a PNG.
- [Subnet calculator](https://tools.jigg.dev/tools/subnet-calculator): Turn an IPv4 or IPv6 CIDR into its address range, mask and host count, and split it into smaller subnets.
- [Gradient & shadow maker](https://tools.jigg.dev/tools/gradient-shadow): Drag to build a CSS gradient or box shadow, then copy the CSS or the Tailwind class.
- [Countdown](https://tools.jigg.dev/tools/countdown): Count down to any date and time, and share a link that keeps counting for whoever opens it.
- [YAML to JSON](https://tools.jigg.dev/tools/yaml-json): Convert YAML to JSON and back, with errors pointed out by line.
- [SQL formatter](https://tools.jigg.dev/tools/sql-formatter): Format SQL for Postgres, MySQL, SQLite, BigQuery and more, with your choice of keyword case and indent.
- [Camera color picker](https://tools.jigg.dev/tools/camera-color): Point your phone's camera at anything and get its hex code and closest color name, live.
- [Workbench](https://tools.jigg.dev/tools/workbench): Chain tools into a pipeline: CSV to JSON, format, encode, hash and more, with every step's output shown.
- [QR scanner](https://tools.jigg.dev/tools/qr-scanner): Scan a QR code with your camera or from a screenshot, and see what's inside before you open it.
- [Color blindness simulator](https://tools.jigg.dev/tools/color-blindness): See an image or a set of colors the way people with red, green or blue color blindness do.
- [Aspect ratio calculator](https://tools.jigg.dev/tools/aspect-ratio): Simplify any size to its ratio, and resize to a ratio without doing the math.
- [Date difference](https://tools.jigg.dev/tools/date-diff): Count the years, months, days and weekdays between two dates, or add days to a date.
- [CSV to JSON](https://tools.jigg.dev/tools/csv-json): Convert CSV to JSON and back, with quoted fields, delimiter detection and typed values.
- [Number base converter](https://tools.jigg.dev/tools/base-converter): Convert whole numbers between binary, octal, decimal, hex and any base up to 36.
- [Color palette](https://tools.jigg.dev/tools/color-palette): Turn one color into a full 50-950 scale and matching harmonies, then export it as CSS or Tailwind.
- [Markdown preview](https://tools.jigg.dev/tools/markdown-preview): Write Markdown with GitHub's extras and see it rendered live, then copy the HTML.
- [Unit converter](https://tools.jigg.dev/tools/unit-converter): Convert length, weight, temperature, volume, area, speed, data and time, all at once.
- [Hash generator](https://tools.jigg.dev/tools/hash-generator): Get MD5, SHA-1, SHA-256, SHA-384 and SHA-512 of text or a file, and check it against a hash.
- [Crontab editor](https://tools.jigg.dev/tools/cron-editor): Build a cron schedule by clicking, read it in plain English, and see exactly when it runs next.
- [JWT decoder](https://tools.jigg.dev/tools/jwt-decoder): Read a JSON Web Token's header and claims, see when it expires, and check an HMAC signature.
- [UUID generator](https://tools.jigg.dev/tools/uuid-generator): Make UUID v4, v7 or ULID IDs in bulk, and inspect any ID to see its version and timestamp.
- [Text diff](https://tools.jigg.dev/tools/text-diff): Compare two texts line by line, with the changed words highlighted.
- [Image compressor](https://tools.jigg.dev/tools/image-compressor): Shrink and resize images to WebP, AVIF or JPEG right in your browser; nothing is uploaded.
- [Regex tester](https://tools.jigg.dev/tools/regex-tester): Test a regular expression live, see every match and group, and read it in plain English.
- [Encode & decode](https://tools.jigg.dev/tools/encoder): Convert text to and from Base64, URL encoding and HTML entities.
- [Contrast checker](https://tools.jigg.dev/tools/contrast-checker): Check two colors against WCAG AA and AAA, and get the nearest color that passes.
- [Word counter](https://tools.jigg.dev/tools/word-counter): Count words and characters, see reading time, and check social post limits.
- [Time zones](https://tools.jigg.dev/tools/time-zones): Find a meeting time that works across cities, hour by hour.
- [JSON formatter](https://tools.jigg.dev/tools/json-formatter): Pretty-print, minify and sort JSON, with errors pointed out by line.
- [QR code maker](https://tools.jigg.dev/tools/qr-code): Turn a link, text or Wi-Fi login into a QR code you can download.
- [Password generator](https://tools.jigg.dev/tools/password-generator): Make a strong random password; it never leaves your browser.
- [Timestamps](https://tools.jigg.dev/tools/timestamp-converter): Convert Unix timestamps to dates and back, in UTC and your time zone.
- [Random color](https://tools.jigg.dev/tools/random-color): Roll a random color and copy it as hex, RGB or HSL.

## Agent tools (WebMCP)

- `list_tools`: Every tool on jigg.dev with its URL, one-line description and tags.
- `open_tool`: Navigates this tab to one of the site's tools, so the person can use it themselves.
- `convert_number_base`: Converts a whole number (any size) from one base (2-36) to binary, octal, decimal, hex and an optional extra base.
- `convert_units`: Converts a value between units of length, weight, temperature, volume, area, speed, data, time.
- `csv_to_json`: Parses CSV (quoted fields and newlines in cells are fine) into JSON rows.
- `json_to_csv`: Turns a JSON array of objects (keys become columns) or of arrays into CSV.
- `date_difference`: Years, months and days between two dates, plus total days, weeks and business days (Mon-Fri).
- `aspect_ratio`: Simplifies a width and height to a ratio (1920x1080 is 16:9), names the nearest common ratio, and optionally solves a new size at that ratio.
- `check_contrast`: WCAG 2.2 contrast ratio of a text color on a background, and which levels (AA, AAA, large text, UI) it passes.
- `color_palette`: A 50-950 shade scale of one color, plus a matching harmony (complementary, analogous, triadic, split, tetradic).
- `generate_password`: A random password from the browser's crypto randomness, with at least one character from each chosen set. Never leaves the device.
- `generate_ids`: Random UUID v4, time-ordered UUID v7, or ULID values.
- `hash_text`: Hex digest of UTF-8 text with MD5, SHA-1, SHA-256, SHA-384, SHA-512.
- `encode_text`: Base64, Base64URL, URL (percent) or HTML entity encoding.
- `decode_jwt`: Reads a JSON Web Token's header and payload. Does not check the signature.
- `format_json`: Pretty-prints or minifies JSON, optionally sorting keys; invalid JSON comes back with the line and column of the error.
- `count_words`: Words, characters, sentences, paragraphs and reading and speaking time of a text.
- `test_regex`: Runs a JavaScript regex over text and returns the matches with their groups, plus a plain-English reading of the pattern.
- `explain_cron`: Describes a five-field cron expression (or @daily style macro) in plain English and lists its next run times in UTC.
- `convert_timestamp`: Reads Unix seconds, Unix milliseconds or a date string and returns it in common formats.
- `run_pipeline`: Runs text through a chain of steps, such as CSV to JSON then sort keys, or Base64 encode then SHA-256, and returns every step's output. The first failing step ends the chain.
- `calculate`: Evaluates arithmetic with the usual order of operations (PEMDAS): + - * / ^, parentheses, mod, 15% of 80, 5!, sqrt() and other functions, pi and e.
- `describe_color`: A color as hex, rgb(), hsl() and oklch(), with the closest CSS color name. Takes any of those forms or a name.
- `inspect_id`: Which UUID version and variant an ID is (or that it's a ULID), and when it was made for time-based IDs (v1, v6, v7, ULID).
- `parse_url`: Splits a URL into protocol, host, path, decoded query parameters and fragment.

## Optional

- [For AI agents](https://tools.jigg.dev/agents): this page for people, with every agent tool's inputs
- [Changelog](https://tools.jigg.dev/changelog): every tool, newest first
- [RSS feed](https://tools.jigg.dev/feed.xml): new tools
- [Sitemap](https://tools.jigg.dev/sitemap.xml)