Free to use
Every app listed here is free: no paywall, no account. Open a tool and get to work.
Uptool lists small, focused web utilities you can open instantly. The date calculator covers add days to a date, subtract days, days between two dates, Unix timestamp to date, date time to Unix, and duration from seconds or milliseconds. The time zones app pairs a multi-city time zone converter on one draggable timeline with a searchable time zone map. ImageToSVG provides in-browser WebAssembly raster to vector conversion, SVG optimization, and K-Means color quantization. The IPv8 calculator summarizes the Internet-Draft address model. Everything runs client-side in the browser: no paywall, no account.
Date calculator
Add or subtract whole days, count days between dates, decode or encode Unix epochs, and break down long durations. Runs in your browser with shareable URLs.
Open Date calculator
Typical uses
You can rely on it when you need to:
- Move a ship date, invoice, or return-to-office day by whole calendar days
- Measure the gap between two milestones with or without clock time
- Turn Unix seconds or milliseconds from logs into a readable local timestamp
- Send one link so teammates reopen the exact same inputs
Results you can paste into email or tickets
Outputs update as you type, and the address bar mirrors your choices so you can bookmark or share a single URL instead of retyping dates in Slack or spreadsheets.
Time zones
Time zone converter for several cities on one timeline plus a time zone map with search, UTC offsets, and saved places. Private, multilingual, shareable links.
Open Time zones
Typical uses
You can rely on it when you need to:
- Line up several cities on one timeline before you send a meeting invite
- Slide a shared window until every office shows an acceptable local hour
- Search a city, read local time plus offset vs UTC, and save a short list
- Share the same cities, date, and range with a link instead of screenshots
Fewer timezone mistakes before you book
Everyone opens the same configured view, so you spend less time correcting “wait, which 9am?” messages and more time locking the slot that actually works.
IP calculator
IPv4 and IPv6 subnet math in the browser, plus a draft-only IPv8 hub (Internet-Draft thain-ipv8): ASN dot notation, routing-prefix classes, reserved ranges, hosts per ASN, guide, and protocol comparison.
Open IP calculator
Typical uses
You can rely on it when you need to:
- Convert 64496.192.0.2.1 style addresses to eight-octet form for lab notes
- See which high-level bucket a routing prefix falls into while reading the draft
- Copy 2^32 and 2^64 scale facts when writing comparisons to IPv4 calculators
Study the draft, not hype
The tools cite draft-thain-ipv8-00 and companion drafts. They help you navigate notation and tables faster than scrolling a PDF on a phone.
ImageToSVG
High-performance in-browser vector tools running 100% locally in WebAssembly. Convert PNG and JPG images to clean SVG vector curves, optimize paths, and extract color palettes.
Open ImageToSVG
Typical uses
You can rely on it when you need to:
- Convert PNG and JPG logos, sketches, and graphics to scalable vector SVG
- Optimize SVG files, strip redundant namespaces, and minify path precision
- Quantize image colors using K-Means and extract dominant palettes
- Process sensitive images 100% locally without uploading to external servers
Client-side WebAssembly vector tracing
All image processing executes locally in your browser with zero latency and zero data leakage. Clean SVG vectors are ready to download immediately.