Powerful tools for developers
Fast, secure and free online tools for conversion, generation and testing. Everything runs locally in your browser.
Convert Coordinates
Convert coordinates between WGS84 (GPS), SWEREF99 TM and RT90. Batch import, map view and address lookup.
Generate Password
Create strong, secure passwords and passphrases. Works offline and all data stays in your browser.
Test Data Generator
Generate realistic Swedish test identities with personal ID numbers, names, addresses and AI profile images. GDPR-safe synthetic data for development and testing.
Create QR Code
Create QR codes online for WiFi, URLs, contacts and calendar events. Download as PNG, SVG or PDF.
Image Converter
Convert images between WEBP, PNG and JPEG. Upload files or enter URL.
Mackan.eu collects free online tools for developers, engineers and IT professionals. All tools run directly in the browser without sending data to any server. Choose from coordinate conversion between WGS84, SWEREF99 TM and RT90, QR code creation for WiFi, contacts and events, high-entropy password generation, and generation of realistic Swedish test identities for GDPR-safe synthetic test data. For technical documentation and analysis there is a JSON Toolbox with support for CSV, XML and YAML conversion, as well as a backup power calculator. Need a free url shortener? Create short links with built-in QR code and no account required. All tools require no login, are ad-free and work offline.
Conversion & Format
Generators
Generate Password
Create strong, secure passwords and passphrases. Works offline and all data stays in your browser.
Create QR Code
Create QR codes online for WiFi, URLs, contacts and calendar events. Download as PNG, SVG or PDF.
Test Phone Numbers Swedish only
Generate test numbers for mobile and landline from PTS reserved number series. Export to CSV and JSON.
Test Data Generator
Generate realistic Swedish test identities with personal ID numbers, names, addresses and AI profile images. GDPR-safe synthetic data for development and testing.
Geo & Coordinates
GeoConvert
Convert geodata files in your browser: KML, GPX, GeoJSON, CSV. Supports SWEREF99 TM, RT90 and WGS84. Your files never leave your device.
Municipality Lookup
Look up municipality code, postal code, coordinates or municipality name for all 290 Swedish communes. Free JSON API, no key required.
Convert Coordinates
Convert coordinates between WGS84 (GPS), SWEREF99 TM and RT90. Batch import, map view and address lookup.
Security & Sharing
Addy Swedish only
Create AnonAddy forwarding addresses in seconds.
Shorten URL Swedish only
Shorten URLs without registration. Create short links with built-in QR code for SMS and social media.
Secret Message
Share secret messages via secure one-time link that self-destructs after reading.
What Is My IP
See your public IP address, geographic location, operator (ASN), reverse DNS and what your browser reveals. Own geo database, no third party.
Other
Address Clusters
Sweden's most company-dense addresses. Ranked list and interactive map from the Swedish company register.
Aptus Swedish only
Convert Aptus HEX keys to decimal values and export results.
Swedish Company Registry
Search 3 million Swedish companies by name, address or registration number. Batch export, map view and registration trends.
Remote Control Timer
Run the countdown from your phone via QR code. No app, no account, encrypted.
Flow Builder Swedish only
Create professional flowcharts with drag-and-drop directly in the browser.
Companies at the Same Address
Find all companies registered at a specific address. Search by street, city or postal code and export as CSV.
Yellow Car Game
Keep score in the classic road trip car game. Start a trip, share the link, everyone in the car counts together. Works offline and without an account.
Interval Timer
Work, rest and number of rounds. Setups for tabata, HIIT and pomodoro.
Sweden Police Events Swedish only
Tactical map based on Swedish Police events in real-time.
Countdown to a Date
Days, hours and minutes left to Christmas Eve, Midsummer or any date.
Pomodoro Timer
25 minutes of focus, a signal when time is up and the time in the tab title.
PTS Registry
Search the PTS case registry, look up phone number operators, and browse NIS incidents. Swedish telecom regulator data.
Upcoming Events Swedish only
See upcoming events at Globe area: Avicii Arena, Hovet, 3Arena and Annexet.
Backup Power Calculator Swedish only
Calculate backup power, fuel consumption and test schedules with RKA profiles.
Timer & Clock
Digital clock and timer with various themes and presentation modes.
Egg Timer
Online egg timer with cooking times for soft and hard boiled eggs.