Generators
5 of 12 tools work right now
Generate QR codes, colour conversions, time-zone overviews and more, all via standard browser APIs, no account or rate limit.
Invoice maker
Build a clean invoice with VAT and download it as a PDF — no accounting subscription or account.
QR code generator
Make a QR code for a link, text or WiFi network.
Colour converter
Switch between HEX, RGB, HSL and OKLCH, type in one field, the rest update live.
Time-zone planner
Plan a meeting across time zones, DST-aware, no math, no account.
Favicon maker
Generate a full favicon set from a single image.
Extract audio from video
Pull the audio track from a video file.
Zip maker
Bundle multiple files into a single ZIP archive.
Calendar invite
Build an .ics file for an appointment or event.
Dutch test data generator
Fictitious but valid BSN, IBAN, Chamber of Commerce numbers and postcodes for dev/test.
Subtitle converter
Convert SRT, VTT, ASS, and SUB between formats while preserving timing.
Domain check
Quickly check whether a domain name is free, plus bulk-check for a list of ideas.
API tester
Test public HTTP APIs from your browser without a Postman account.
Frequently asked questions
Which QR codes scan on every phone?
A standard QR code with URL, text or WiFi network works on every recent phone (iOS and Android). What doesn't always work: stylised QRs with logos in the middle, if the design eats into the error-correction blocks, it stops scanning. Our generator defaults to maximum error correction (level H) so a small logo can fit.
What's the difference between RGB, HEX and OKLCH?
Three ways to express the same colour. RGB and HEX (#ff8800) are familiar from CSS and design tools. OKLCH is newer and perceptually uniform, a step in 'L' (lightness) actually looks like an equal step to your eye, which isn't true for HEX/RGB. For design tokens and accessible colour schemes, OKLCH wins.
How does a time zone with daylight saving work?
Time zones like 'Europe/Amsterdam' know themselves when the clock jumps, it's a lookup in the IANA database in your browser. Planning a meeting between Amsterdam and San Francisco on a date that crosses a DST boundary works automatically. No UTC+1 or UTC+2 to compute by hand.
Other categories
This tool runs entirely in your browser. Nothing is uploaded or stored on a server.