Building real things, in public
Notes from DEMHA FUTURE — how we build apps fast with AI, and what we learn.
Unit Converter — free online tool
Convert length, weight, temperature and more for free online, right in your browser with nothing uploaded.
Unix Timestamp Converter — free online
Turn a Unix timestamp into a real date in UTC and your local time, free and online, right in your browser with nothing uploaded.
UPC / EAN Check Digit Calculator — free online
Compute or validate the check digit for UPC-A, EAN-13, EAN-8 and ITF-14 barcodes, free and online, right in your browser with nothing uploaded.
URL Encoder / Decoder — free online
Encode or decode URLs and query parts online, right in your browser, with nothing uploaded. Free and quick to use.
Self-Employment Tax Calculator — free online
Estimate your 1099 self-employment tax online for free, right in your browser. See Social Security, Medicare and the deductible half — nothing uploaded.
User-Agent Parser — free online tool
Paste any User-Agent string and read it in plain words: browser, version, engine and device. Free and online, right in your browser, nothing uploaded.
UTM Builder — free online link tagging tool
Build clean, tagged campaign links online for free, right in your browser. Nothing is uploaded, and the encoding is handled for you.
Bulk UTM Builder — free online tool
Build tracked UTM links in bulk online, free and right in your browser. Paste many URLs at once, nothing is uploaded.
UTM Link Decoder — free online tool
Paste a link with UTM tags and read every tracking value in a clean table, free and online, right in your browser with nothing uploaded.
UTM Naming Convention Builder — free online
Set your UTM rules once, then check any campaign link follows them. Free and online, right in your browser, nothing uploaded.
Get new posts
Soon you'll be able to drop your email and get new posts — no account, no spam.
Email sign-up isn't live yet — nothing is collected for now.