Observation Log
A private observation log in one HTML file on your machine: no account, no cloud, no server to talk to.
This is not a screenshot. It's the real tool, running right here: go on, put something in it.
Forged into a knife, this tool ages with use: the blades you reach for wear soft, entries you tend keep their bloom, and the years travel with the file through every reforge.
You finally caught the Ring Nebula on a night of good seeing, and by breakfast the details had already gone soft. The Observation Log keeps each session honest: the object, the night, seeing rated 1 to 10, and a notes box for equipment and everything else the sky gave you.
What it keeps
- Objectshort text
- Night ofdate
- Seeing 1-10number
- Equipment & notesnotes
Standing facts
- One HTML file. Opens in any modern browser, on any operating system.
- No account. No login, no sign-up, no e-mail wall.
- No cloud. Nothing leaves your browser: no server, no telemetry, no analytics.
- Yours forever. The file keeps working whether or not Offline.Ltd does.
- Ages with use. Entries you tend keep their bloom; the years travel with the file through every reforge.
In ten years
Whatever you put in (Object, Night of, Seeing 1-10 and Equipment & notes) stays inside the file itself. There is no account to lapse, no plan to be sunset, no migration e-mail with a deadline in it. A decade of observation log entries is a decade of your own handwriting, kept in a document you can back up like any other.
If Offline.Ltd closes tomorrow, nothing on your machine notices. That isn't a marketing promise; it's simply what a file is.
Getting your data out
Export to CSV from inside the tool and open it in anything: a spreadsheet, another app, a text editor. Or keep the HTML file: it is plain, readable, and inspectable; you can open it in a text editor and see your own rows sitting there. No export queue, no "we'll e-mail you a link within 48 hours", no format that only one vendor can read.
Copy the file to a USB stick, a NAS, a folder your devices already sync. It runs on Windows, macOS, Linux, Android and iOS, online or off, because a browser is the only thing it ever needed.
Who else sees this
Nobody. Your Object, Night of, Seeing 1-10 and Equipment & notes never leave the file on your own disk. There is no account, no telemetry, no analytics, and no code in the file that opens a network connection, pull the cable and watch it carry on working. How privacy works across the Hobby tools →
Questions people ask
How do amateur astronomers keep an observation log?
One entry per object per night: what you looked at, when, how the seeing was on a 1-to-10 scale, and which scope and eyepiece you used. Over a year it becomes a record of your sky, in your handwriting, so to speak.
Does this astronomy log work offline at a dark-sky site?
Yes, completely. It's a single HTML file running in your browser — no signal required, which is convenient, since the best skies tend to be where the signal isn't. Your log never leaves your device.
What does the seeing rating mean and why track it?
Seeing is how steady the atmosphere is; the log gives you a simple 1-to-10 field for it. Track it and you'll learn which observations to trust and which nights flattered you.
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Fits your knife at weight 1. Nothing here is final, Knife follows Life. Reforging within your tier is free, forever. Add it, drop it, reforge it later; the file stays yours either way.