off.tools

Offline by default. Online only when you ask.

A single, self-contained HTML file — a small toolbox for everyday network and sysadmin work. Links, command snippets, subnet/IP math, a MAC lookup, a diff tool, world clocks, a time calculator, reusable text blocks, and more. No install, no server, no accounts. Nothing is sent anywhere.

Work in progress. This is an early preview, not an official release yet — details and the file itself may still change. Have a look, try it out, and tell me what's broken.

Download off.tools.html It's one file. Save it, then double-click it — or open it in your browser first.

How to use it

Open off.tools.html in any modern browser — from a disk, a USB stick, or a network share. It runs entirely on your machine.
Use any tool from the sidebar. Everything computes locally and keeps nothing; whatever you type is gone when you reload the page.
Make it yours (optional): open Customize to add your own links, snippets, clocks, accent color and language, then Save as HTML to bake it into your own standalone copy. That saved file is your version from then on — keep it, carry it, reopen it anywhere, still fully offline.

A few good-to-knows

Offline by default.

A Check links button runs a one-off, ~30-second reachability test on your Link Board sites, then drops back to offline on its own. It only reaches out when you press it — no background polling, no permanent connection.

A saved copy is cleartext.

Anything you save into a customized file is written into the .html as readable text. Treat a customized copy as sensitive. For files on a shared drive, Lock Confidential Link addresses keeps confidential addresses out of the saved file.

Keyboard.

Ctrl+K / ⌘+K opens a quick-jump palette; Esc closes dialogs.

Verify the download

A file can't vouch for itself, so integrity lives here, not inside the page. After downloading, check that its SHA-256 matches the published value:

sha256sum off.tools.html

Expected (also in off.tools.html.sha256) e8f719b0b0ec5d5eb79525122f292537493e564ac0e7cc7359f6f383dc36e130

On Windows: certutil -hashfile off.tools.html SHA256. Since this is a preview, expect the published hash to change whenever the file is updated — always compare against the sidecar above.