Looking for help with a particular tool? Find it below. For explanations that cover a whole task, start with the topic guides.
Encoding
- Base64 Text Guide
Encode and decode UTF-8 text to and from Base64, URL-safe optional.
- Base64 File Guide
Turn any file into a Base64 data string, or decode one back to a file.
- URL Encoder Guide
Percent-encode and decode URL components.
- HTML Entities Guide
Escape and unescape HTML special characters.
- Text to Binary Guide
Convert text to its binary representation and back.
- Text to Unicode Guide
Show the Unicode code points of a string, and rebuild a string from them.
- NATO Alphabet Guide
Spell out text using the NATO phonetic alphabet.
- String Obfuscator Guide
Obfuscate part of a string while keeping it readable.
- SafeLink Decoder Guide
Extract the real destination behind an Outlook SafeLink.
- Basic Auth Header Guide
Build an HTTP Basic Authorization header from a user and password.
Formats
- JSON Formatter Guide
Validate, pretty-print and minify JSON, with optional key sorting.
- JSON Viewer Guide
Explore a JSON document as a collapsible tree or as a table of records, with a live count of nested values.
- JSON Minifier Guide
Strip all whitespace from JSON to shrink it.
- JSON to YAML Guide
Convert JSON documents to YAML.
- YAML to JSON Guide
Convert YAML documents to JSON.
- YAML to TOML Guide
Convert YAML documents to TOML.
- TOML to YAML Guide
Convert TOML documents to YAML.
- JSON to TOML Guide
Convert JSON documents to TOML.
- TOML to JSON Guide
Convert TOML documents to JSON.
- XML Formatter Guide
Pretty-print XML with two-space indentation and report parsing errors.
- XML to JSON Guide
Convert XML documents to JSON.
- JSON to XML Guide
Convert JSON documents to XML.
- JSON to CSV Guide
Flatten a JSON array of objects into CSV.
- SQL Prettify Guide
Reformat SQL queries so they are readable.
- Markdown to HTML Guide
Render Markdown to HTML in the browser.
- YAML Viewer Guide
Validate and explore a YAML document.
- List Converter Guide
Convert between line lists, CSV, JSON arrays and other list formats.
Crypto
- Hash Text Guide
Compute MD5, SHA-1, SHA-256 and SHA-512 digests of text.
- File Hash Checker Guide
Hash a file with MD5, SHA-1, SHA-256 and SHA-512, and check it against a published digest.
- SSH Key Generator Guide
Generate an Ed25519, ECDSA or RSA key pair, with the OpenSSH public key and fingerprints.
- HMAC Generator Guide
Compute keyed HMAC signatures with a choice of digest.
- UUID Generator Guide
Generate v4 UUIDs, single or in bulk.
- ULID Generator Guide
Generate sortable ULIDs, single or in bulk.
- Token Generator Guide
Generate random tokens and passwords of a chosen length and charset.
- bcrypt Guide
Hash a password with bcrypt, or verify one against a hash.
- AES Encryption Guide
Encrypt and decrypt text with AES.
- TLS Certificate Decoder Guide
Inspect the domains, dates, issuer, and fingerprint in a PEM certificate without mistaking decoding for trust verification.
- RSA Key Pair Guide
Generate an RSA public and private key pair, and check whether two keys match.
- BIP39 Mnemonic Guide
Generate a BIP39 mnemonic phrase and derive its seed.
- Password Strength Guide
Estimate how long a password would take to crack.
- PDF Signature Checker Guide
Inspect the digital signatures embedded in a PDF.
Network
- IP & Geolocation Lookup Guide
Show your public IP (or any address) with its country, city, coordinates and ISP.
- HTTP Request Tester Guide
Send an HTTP request from the browser and inspect responses.
- CORS Checker Guide
Check whether a URL can be read from this browser origin and inspect visible CORS headers.
- curl Tester Guide
Parse, explain and rebuild curl commands locally.
- curl Converter Guide
Convert curl commands into JavaScript fetch, Axios or Python requests code.
- gRPC Tester Guide
Build grpcurl commands and test gRPC-Web endpoints from the browser.
- DNS Lookup Guide
Resolve A, AAAA, MX, TXT, NS, SOA, CAA and SRV records over DNS-over-HTTPS.
- WHOIS Lookup Guide
Show registrar, registration and expiry dates, status and nameservers for a domain.
- IPv4 Subnet Calculator Guide
Work out the network, broadcast, mask and host range for a CIDR block.
- IPv4 Address Converter Guide
Convert between dotted, decimal, hex and binary IPv4 forms.
- IPv4 Range Expander Guide
Expand an IP range into the CIDR blocks that cover it.
- IPv6 ULA Generator Guide
Generate a random IPv6 unique local address prefix.
- MAC Address Lookup Guide
Look up the vendor behind a MAC address OUI.
- MAC Address Generator Guide
Generate random MAC addresses, with optional prefix.
- Random Port Generator Guide
Pick candidate port numbers from a chosen range without checking the network.
- WebSocket Tester Guide
Open a WebSocket from the page, send frames and watch what the server sends back.
- IPv6 Expander Guide
Expand, compress and classify an IPv6 address, with prefix and embedded IPv4 support.
- HTTP Header Parser Guide
Turn a pasted header block into a clean table, including cookies and repeated fields.
- HTTP Header Builder Guide
Build a tidy header block from key/value lines, with common security headers ready to add.
- WebSocket Frame Parser Guide
Decode a raw WebSocket frame from hex and explain its opcode, length and payload.
- Port Reference Guide
Search the common TCP and UDP ports with their service names and a short description.
- SSH Tunnel Builder Guide
Assemble an ssh -L, -R or -D tunnel with the right ports, identity file and keepalive options, then copy the command.
- Email Header Analyzer Guide
Parse raw email headers, list the delivery hops and show where the time went.
- Open Graph Debugger Guide
Extract Open Graph and Twitter Card tags from pasted HTML and preview the shared card.
- Network Info Guide
Show what this browser exposes about its connection, device, screen and locale.
- API Mock Response Builder Guide
Describe fields once and generate realistic mock JSON for an API response.
- Webhook Tester Guide
Sign, verify and send a test webhook in the Stripe, GitHub or Shopify format.
- SNAP BI Asymmetric Signature Guide
Build, sign and verify the SHA256withRSA signature used by Bank Indonesia's SNAP BI standard.
DevOps
- Dev Ops Guide
Describe a Linux problem and get safe commands, flag explanations, a risk level and the next troubleshooting steps.
- systemd Service Builder Guide
Turn a foreground application into a reviewable Linux service, then check its unit, startup behavior, and logs.
- tar Command Builder Guide
Understand the source base, archive path, compression, excludes, and extraction safeguards in a GNU tar command.
- rsync Command Builder Guide
Read source trailing-slash behavior, preview directory transfers, and understand destination deletion before running rsync locally or over SSH.
- find Command Builder Guide
Assemble a find command with name, type, size, age and depth tests, then choose to print, delete or exec on each match.
- xargs Builder Guide
Build and explain an xargs command — null input, batch size, parallelism and a replace string, with a note on each flag.
Web
- JWT Parser Guide
Decode, live-edit and verify JSON Web Tokens.
- JWT Encode Guide
Create, edit and sign JSON Web Tokens from header and payload JSON.
- JWT Expiry Editor Guide
Edit iat, nbf and exp claims on a JWT and re-sign it without touching JSON by hand.
- UTM Builder Guide
Build and parse UTM campaign URLs with source, medium, campaign, term, content and id.
- URL Parser Guide
Break a URL into its parts and query parameters.
- User Agent Parser Guide
Read the browser, engine, OS and device from a user-agent string.
- Microphone Recorder Guide
Check a microphone, watch its level and peak, and record a clip to play back or download.
- OpenAPI Viewer Guide
Read an OpenAPI or Swagger document and list its operations, parameters and responses.
- MIME Types Guide
Look up the MIME type for a file extension.
- HTTP Status Codes Guide
Reference list of HTTP response status codes and their meaning.
- Meta Tag Generator Guide
Generate HTML meta tags for a page.
- Keycode Info Guide
Press a key to see its code, key and modifier state.
- Slugify Guide
Turn any text into a clean URL slug.
- OTP Generator Guide
Generate and verify time-based one-time passwords.
- Device Information Guide
Show what the browser reports about the current device.
- QR Code Generator Guide
Generate a QR code from text or a URL.
- Wi-Fi QR Code Guide
Build a QR code that joins a Wi-Fi network.
- QR Code Editor Guide
Restyle a QR code — module shapes, gradient colours, logo, transparent background.
- Sticker Maker Guide
Create PNG stickers with shapes, text decoration, outlines and simple background removal.
- SVG Placeholder Guide
Create a placeholder image as an SVG.
- Camera Recorder Guide
Record a short video from the webcam in the browser.
- Image Metadata Viewer Guide
Read the EXIF, GPS, comments and colour data hidden inside a photo, without uploading it.
- Image Compressor Guide
Resize and re-encode an image in the browser — cap its dimensions, pick a format and quality, then download the smaller file.
- EXIF Remover Guide
Strip EXIF, GPS and other hidden metadata from a photo by re-encoding it in the browser.
- Image Format Converter Guide
Convert a picture between JPEG, PNG, WebP and AVIF, with a quality slider and a before-and-after size.
- Watermark Tool Guide
Draw a text watermark onto a picture, choosing the corner, size, colour and opacity.
- Photo Resizer by Target Size Guide
Shrink a photo until it fits a size in kilobytes, keeping the highest quality that still fits.
- Screenshot Privacy Cleaner Guide
Pixelate or black out parts of a screenshot before sharing it.
- Background Remover Guide
Clear a plain background from an image by flooding in from the edges.
- Zip Builder Guide
Bundle several files into a zip archive in the browser, with a choice of compression level.
- PDF Page Counter and Info Guide
Read a PDF to see its page count, page sizes, version and document information.
- PDF Page Extractor Guide
Keep only the pages you choose from a PDF and download the rest as a new file.
- PDF Merger Guide
Join several PDFs into one document, in the order you set.
- Text to PDF Guide
Write plain text out as a PDF, with wrapping, page size, margins and page numbers.
- HTML Editor Guide
A small rich-text editor that exports clean HTML.
- JavaScript Playground Guide
Write JavaScript with syntax highlighting and run it in the page, reading its console output, return value and timing.
- TypeScript Playground Guide
Try typed JavaScript, read transpilation errors and run coding exercises in a browser Worker.
- Python Playground Guide
Run Python with Pyodide, answer interactive input and read output from coding exercises and pyramid patterns.
- Ruby Playground Guide
Read Ruby output, answer interactive input and try classes, prime-number exercises and pyramid patterns.
- C Playground Guide
Compile and run C in your browser, read compiler errors, answer interactive input and try prime-number, struct and pyramid exercises.
- C++ Playground Guide
Compile and run C++20 in your browser, read Clang diagnostics, answer interactive input and try classes, prime-number and pyramid exercises.
- WhatsApp Link Generator Guide
Turn a phone number and a message into a wa.me click-to-chat link.
Workflow
- nginx Config Generator Guide
Build an nginx server block for a static site, a single-page app, PHP or a reverse proxy.
- nginx Reverse Proxy Wizard Guide
Step through domain, upstream, TLS and extras to get a reverse proxy server block.
- Crontab Generator Guide
Build a cron expression and read it back in plain language.
- chmod Calculator Guide
Convert between octal and symbolic Unix file permissions.
- Docker Run to Compose Guide
Turn a docker run command into a docker-compose service.
- Docker Logs Grep Guide
Filter docker compose logs with grep-style context, invert and dedupe modes.
- Log Redactor Guide
Remove common sensitive patterns from a log, add exact-text replacements, and review what automated detection cannot catch.
- Log Parser Guide
Parse JSON Lines, Apache/Nginx access logs, syslog, logfmt and plain logs into a searchable table.
- Dockerfile Builder Guide
Build a Dockerfile from a form, with multi-stage presets for Node, Python, Go, Nginx and more.
- Git Cheatsheet Guide
A quick reference of the Git commands I keep forgetting.
- Regex Tester Guide
Test a regular expression against sample text with live matches.
- Regex Replace Tester Guide
Preview regex find-and-replace results with capture group references and live highlighting.
- Cron Next Runs Guide
Preview the next scheduled runs of a cron expression in local time or UTC.
- Regex Cheatsheet Guide
A quick reference of regular-expression syntax.
- JSON Diff Guide
Compare two JSON documents and highlight the differences.
- Text Diff Guide
Compare two blocks of text line by line.
- Timestamp Converter Guide
Convert between Unix timestamps, ISO strings and local time.
- Time Zone Converter Guide
Read a log timestamp in one zone and see the same moment in UTC, Jakarta and others.
Text
- Lorem Ipsum Guide
Generate placeholder paragraphs, sentences or words.
- Text Statistics Guide
Count characters, words, sentences, lines and reading time.
- Emoji Picker Guide
Search emoji by name and copy them.
- Numeronym Guide
Turn long words into numeronyms like i18n.
- ASCII Text Guide
Render text as large ASCII-art banners.
- Case Converter Guide
Switch text between camelCase, snake_case, kebab-case and more.
- Line Comma Formatter Guide
Add commas, quotes, arrays or SQL IN formatting to one-item-per-line lists.
- .env Diff Checker Guide
Read configuration differences between staging and production without copying secret values into a report.
- .env Key Sorter Guide
Sort the keys in a .env file alphabetically, keeping each comment with its key and optionally dropping duplicates or aligning values.
- sed Simulator Guide
See how first versus global replacement, whole-match insertion, deletion, and selected-line printing affect sample text.
- grep Simulator Guide
Read matching lines, inverted selection, context separators, counts, and matching-text output using a local sample instead of files.
- sed Replacement Builder Guide
Build a sed command to replace text, delete matching lines or print only matches, with in-place editing and backups.
- grep Pattern Builder Guide
Build a grep command with the right regex style, recursion, includes and context lines, then copy it.
- Currency Formatter Guide
Format a number as a currency amount with thousand separators and a symbol, in Indonesian or English style.
- Number to Words Guide
Spell an Indonesian number out in words, for invoices and receipts.
- Typo Spotter Guide
Flag double spaces, stray spaces around punctuation, repeated words and informal Indonesian short forms.
- WhatsApp Message Formatter Guide
Format a WhatsApp message with bold, italic, strikethrough, monospace and lists, with a live preview.
Convert
- Number Base Converter Guide
Convert integers between binary, octal, decimal and hex.
- Roman Numerals Guide
Convert between Roman numerals and decimal numbers.
- Temperature Converter Guide
Convert between Celsius, Fahrenheit and Kelvin.
- Color Converter Guide
Convert colors between HEX, RGB, HSL and more.
- Fuel Economy Converter Guide
Convert fuel economy between km/L, L/100 km and US or UK MPG.
- CLI Table Converter Guide
Turn aligned terminal output such as docker ps or df into a Markdown table, CSV or TSV.
- Google Maps Link Parser Guide
Pull the latitude and longitude out of a Google Maps link and export it as JSON, CSV, SQL or GeoJSON.
Math
- Math Evaluator Guide
Evaluate a mathematical expression, with variables and functions.
- ETA Calculator Guide
Estimate a finish time from progress, elapsed time and remaining work.
- Percentage Calculator Guide
Work out percentages, increases and decreases.
- Interest Calculator Guide
Calculate deposit or loan interest after tax, with flat, effective, annuity, compound, tiered, step-up and floating methods.
- Indonesian Tax Calculator Guide
Read historical Indonesian tax calculations, distinguish taxable bases from invoice totals, and check which scenarios are actually supported.
- Take-Home Pay Calculator Guide
Estimate Indonesian net salary from gross pay, with PPh 21 and the employee share of BPJS broken out.
- Loan Calculator Guide
Work out a fixed-rate loan payment, its amortisation schedule and the interest saved by paying extra.
- Date Calculator Guide
Add or subtract days, weeks, months and years, or measure the duration and business days between two dates.
- Chronometer Guide
A simple stopwatch with laps.
- Benchmark Builder Guide
Run a JavaScript snippet repeatedly in your browser and display approximate timings.
- Random Generator Guide
Pick from a list with a spin wheel, slot machine, random card, dice or ticker animation.
- Discount Calculator Guide
Work out a final price, a discount percent, or the original price from a discount and a final price.
- Unit Price Comparator Guide
Compare products by unit price so different pack sizes can be ranked on the same scale.
- Age Calculator Guide
Work out an age in years, months and days, with totals and the next birthday.
Data
- SQL Insert Generator Guide
Turn JSON or CSV rows into SQL INSERT statements for MySQL, PostgreSQL, SQLite or SQL Server.
- Email Normalizer Guide
Normalize email addresses to a canonical form.
- Phone Parser Guide
Parse and format phone numbers by country.
- IBAN Validator Guide
Validate an IBAN and read its country and check digits.
- NIK Parser Guide
Parse Indonesian NIK into region codes, birth date, gender and serial number.
- JSON Schema Validator Guide
Validate a JSON document against a JSON Schema (draft-07 subset) and list every problem with its JSON Pointer path.
- JSON Path Explorer Guide
Evaluate JSONPath expressions against JSON, list every match with its path, and build expressions by clicking a tree.
- CSV Viewer Guide
Open a CSV, TSV or pipe-separated file, filter it and sort it column by column in a table.
- CSV and JSON Converter Guide
Convert CSV to JSON, or JSON back to CSV, with configurable delimiter and pretty-printing.
Games
- Typing Speed Test Guide
Measure WPM and accuracy with live per-character feedback and a restartable test.
- Gamepad Tester Guide
See every axis and button of a connected controller, with the pressed buttons lit up.
- 2048 Guide
Slide and merge numbered tiles to reach 2048, with undo, best score and keyboard or swipe controls.
- Memory Match Guide
Flip cards and find matching pairs, with move count, timer and difficulty levels.
- Minesweeper Guide
Clear a grid without hitting a mine, with flags, first-click safety and difficulty levels.
- Snake Guide
Steer a growing snake to eat food without hitting the walls or yourself.
- Tetris Guide
Stack falling tetrominoes and clear lines, with next-piece preview, hold and levels.
- DevOps Tycoon Guide
Manage servers, traffic and incidents as a DevOps engineer — buy capacity, survive outages and keep the service profitable.