What leaves your device

At most five network requests, and only two you didn’t ask for

What matters is which ones happen on their own. Three of the five are things you do, such as running a step or pressing a button, and are no more surprising than saving a file. The other two happen by themselves, so they come first. You can switch off either.

Two run on their own

One is on until you turn it off; the other is off until you turn it on.

Request	When	Recipient	What is sent
Update check	At startup, until you turn it off in Settings	GitHub	A request for the number of the latest release, and nothing about you or your work. Your IP reaches GitHub as part of the connection, as it would for any web page; I receive nothing from it.
Usage count	Only if you agree when asked on first run; then at most once a day	Nocturne server	The event, the app version, and a random installation number that changes every month. No IP address is stored. Decline and nothing is ever sent, and you are not asked again.

Three happen only when you do something

Each of these waits for you. Two of them have a Send button. The first does not, so it is described here in full.

Request	When	Recipient	What is sent
Colour calibration	When you run the Colour step with Photometric (SPCC) chosen. Its other setting, Sky balance, does the whole job on your computer and asks nothing	VizieR, the astronomical data centre in Strasbourg	Where your picture points: its position on the sky and how wide a patch it covers, so the catalogue can send back the true colours of the stars in it. The calibration measures against those real stars rather than guessing. Your picture is never sent, and nothing about you is. Your IP reaches VizieR as part of the connection.
Problem report	Only when you press Send, in Nocturne or on the support page	Nocturne server	What you typed, the details shown in the form, and, from Nocturne only, the diagnostic log unless you untick it. The IP is kept to rate-limit the form and deleted after four weeks.
Gallery submission	Only when you tick the box and press Send, once per picture	Nocturne server	The finished picture, its capture details and, if you plate-solved it, where it is on the sky. Never your location. The IP is kept to rate-limit the form and deleted after four weeks.

The update check

At startup, Nocturne asks api.github.com whether a newer version has been released.

• Your IP address reaches GitHub as part of that request, the same way it does for any website you open. That is how the internet works rather than a choice Nocturne makes, but you should know it happens.
• Nothing is sent about you, your machine, your settings or your images. The request asks a question and reads an answer.
• I receive nothing from it. The request goes to GitHub, not to me. I cannot see who made it, or that you made it at all.
• You can turn it off: Settings → Check for a new version at startup.

Your images

Nocturne never uploads an image, a stack, a project file or a FITS header on its own. Everything you open stays on your device unless you deliberately send it, and there are three ways to do that: the Send a stack form, a problem report with a screenshot attached, and the gallery described below. Each one is a button you press, and each says what it does before you press it.

The gallery

Nocturne's Export step can send a finished picture to the gallery. Nothing is sent unless you tick the box and press the button.

• What is sent: the finished picture as you see it, and the details shown with it: the handle you typed, the object, the frame count, the exposure, the total integration, the capture date and the camera.
• Where the picture is on the sky. If you plate-solved the picture in Nocturne, its sky position (the coordinates of its centre, its scale and its rotation) goes with it, so it can be placed on the planner’s sky view. It describes the stars in the photo, not you or where you were.
• What is never sent: your location. Nocturne always leaves it out of the caption, and the server has no field for it.
• Your handle is public and is whatever you type. It is the only name shown on the gallery, and it is not checked against anything, so pick the one you want to be known by.
• Nothing appears automatically. Every submission waits for me to look at it. If I publish it, the picture is resized and re-encoded, which is also where any remaining EXIF is dropped. If I do not, the file is deleted rather than kept.
• The IP address of the upload is recorded to rate-limit the form and is deleted after four weeks, like the others on this page.
• A published picture may also appear on the planner. The session planner can show a photograph beside the object it suggests, chosen by hand from pictures already on the gallery. It is the same picture, the same handle and the same capture details, on another page of this site; nothing further is sent or collected.
• See it in the sky opens the planner’s sky view on the object in a picture, from the place you saved on the planner, or from Greenwich if you have not saved one. Nothing about where you are is sent by opening it. If you type a place there, its name goes to Open-Meteo to find it, as on the planner; typed coordinates are only rounded to about a kilometre, and nothing is sent for them. The place is then kept in your browser for the planner too.
• Following your phone in the sky view. On a phone, a tap on the compass turns the sky to where the phone points. That reads the phone’s compass and tilt in your browser; the readings are not sent anywhere or kept. Safari asks your permission first.
• To have a published picture removed, ask through the support form. It will be taken down from the gallery and from the planner, and the file itself is deleted, not hidden. There are no accounts, so you can’t do it yourself.

This website

Since 16 October 2026 this site counts its visits. I want to know whether anyone arrives after I post about Nocturne, and whether they go on to download it. The counting is done by Umami, an open-source program that runs on Nocturne’s own server at analytics.nocturneastro.com. Nothing is sent to Google or to any other company, and nothing is shared or sold.

• One cookie, and only on the shop’s account page. When you sign in there, the shop sets one cookie that keeps you signed in. It holds nothing else and expires after a day. The rest of the site sets no cookies.
• What is recorded for each page you open: the time of the visit, the page’s address and title, the page that linked you here, your browser, operating system and type of device, your screen size and language, and your country, estimated from your IP address. Never your region or town.
• Your IP address is not stored by the counter. It is used for that estimate and to tell visitors apart without a cookie. The counter mixes it with the line your browser sends to identify itself, a secret key and a value that changes at the start of every month, and keeps only the resulting number. That number cannot practically be turned back into your address. Within one month your visits can be grouped together; the next month you count as a new visitor.
• A few clicks are counted too: a download, with its platform and version; a sample file; Try it on sample data; a click on the Facebook or Instagram link; opening Show in sky, with the target and whether it came from a card, a shared link or the gallery; entering a place in the gallery’s sky view; and Plan tonight or Use my location, but never the place. Nothing you type is recorded.
• The Facebook and Instagram links are plain links. No page here loads anything from Meta, so nothing reaches Facebook or Instagram unless you click one. After that you are on their site, and their privacy terms apply.
• Only the page itself is recorded, not the rest of its address. Anything after a ? or a # is left out. That covers the tracking codes some sites add to links, and the diagnostic details Nocturne puts after the # when it opens the support page.
• To opt out, turn on Do Not Track in your browser, and the visit counter counts nothing (the daily download tally below still counts a click on Download). Chrome and Edge still offer that setting; Safari and Firefox no longer do. Blocking analytics.nocturneastro.com with a content blocker also works, and every page works the same without it.
• The counts are kept until I delete them, and only I can read them.
• Downloads are also counted separately. Clicking Download adds 1 to a daily tally: a date and a number. No IP address is kept, and nothing that identifies you or your browser beyond a check that filters out obvious bots.
• Until 17 September 2026 that click also recorded your IP address. Nothing ever read it; it was collected because the table had a column for it. It has been deleted and the column is gone.
• The web server keeps ordinary access logs, as every web server does. They include the IP address of each request and are deleted after two weeks. Once a night a script reads them to count the downloads that actually finished, and keeps only the daily totals, not the addresses. The logs are used for nothing else and shared with no one. Requests to the visit counter itself are not written to these logs, so the counting leaves no IP address behind anywhere.

If you donate a stack

Send a stack takes the file and whatever else you fill in: the target, telescope, camera and mount, why you are sending it, a note, a name and an email. Only the file and the consent box are required.

• The observing site is removed from the file’s header. The page reads the header in your browser and blanks the standard entries for the observing site, such as its latitude, longitude and height, and the observer’s name. A Seestar also writes its serial number into the telescope entry, and the page blanks that entry too. If your browser cannot run the page, the server removes them when the file arrives. The image itself is not changed.
• The server checks again on arrival and blanks any such entry that is still there.
• The capture date and the target’s position in the sky stay in the file. They say where you pointed, not where you were.
• A TIFF with GPS location data is refused, by the page before anything is sent and again by the server.
• The file, your email and the IP address of the upload are deleted automatically after four weeks by a scheduled job. Until then your email is never shown, and I use it only if I need to ask you about the file. The IP address is recorded only to rate-limit uploads.
• The details on the form are kept after that, without the file and the email: the name you gave for the credit, the target, the telescope, camera and mount, the frames and exposure read from the file, why you sent it and your note. The file’s name, type, size and upload date are kept too.
• The credit is the name you gave, shown in Nocturne as a Photon Donor. Leave the name empty and there is no credit.
• A donated stack is never published, shared or sold, and it never becomes sample data.
• To have the file or your details deleted sooner, ask through the support form.

Usage counting — opt-in, and off unless you say yes

Downloads do not show whether Nocturne is actually being used, so this count informs support and maintenance decisions. Nocturne asks once, on first run. If you say no, nothing is ever sent and you are not asked again. If you say yes, this is the entire protocol:

• once, the first time it runs: {"event": "first-run", "version": "0.34.0"}
• at most once a day, while you use it: {"event": "daily", "version": "0.34.0", "id": "7f3a…"}

That is everything. There is no third message and no other field: no operating system, no locale, no screen size, no hardware, no file names, no targets, nothing about your images, and no timestamp finer than the date.

About that id. It is a random number your copy of Nocturne generates, and it is replaced every calendar month. Within a month it lets me count installations rather than launches. Across months nothing links one number to the next, so there is no history of you and no way to build one. Strictly speaking, that makes it a pseudonymous identifier rather than an anonymous one while it lasts. It isn’t derived from your computer, your account or anything else about you, and it is a single line in ~/.nocturne/settings.json.

Your IP address is not stored. It reaches the server with the request, as with any request, but the server is set to keep no log of requests to it at all, and the table it writes to has no column for an address or a time of day. You can change your answer any time in Settings → Count my use of Nocturne.

Problem reports

If you send a problem report, from the support page or from Nocturne’s Help menu, what you typed is stored on the Nocturne server and read only by Andreas. It is not handled by a ticketing service or shared with anyone else.

Your email address is optional. It is used to reply to you about that report and for nothing else: no list, no announcements. Leave it blank and the report is anonymous, though then there is no way to tell you what happened.

Nocturne fills in its version, your operating system, your screen size and window size, and a diagnostic log. Nothing is sent until you press Send. Every value is shown in the form for you to read, edit or delete first, and the log is shown in full rather than attached out of sight.

The diagnostic log records what Nocturne did, not what your computer is: the steps you ran, the tools it called and their versions, and any errors. It contains file paths, and a file path contains folder names, which can include your name. So you can read the log first, and leave it out with a single tick. If you do, I may not be able to work out what went wrong, since there is usually no way to ask you afterwards.

It is sent only when you report from inside Nocturne. Reporting from the support page sends no log: the file is on your computer and I would rather not ask you to go and find it.

Two things expire on their own. Any screenshot or file you attach is deleted after 28 days, along with the IP address the submission came from. The diagnostic log is deleted when I delete the report, or after 28 days, whichever comes first, even if the report is still open. The text of the report is kept, because it describes the bug and there is usually no way to ask you about it again.

The session planner

The session planner is the one page on this site that needs JavaScript, and the one that talks to another service. On a first visit nothing about where you observe from is sent until you type a location and press the button. Before that, the only request is the visit count described under This website, which goes to this site’s own server and records only your country.

When you press it, two requests go out, both to Open-Meteo and neither to us. The first sends the place name exactly as you typed it, so if you type your street rather than your town, the street is sent. It gets coordinates back. The second sends those coordinates, rounded to two decimal places (about a kilometre), and gets the forecast. Our server never receives the place or its coordinates, and the visit count records only your country, never your town or where you observe from. All of the astronomy is worked out on your own computer.

Use my location skips the typing: your browser works out where you are, but only after it has asked you and you have allowed it. The coordinates it gives the page are rounded the same way, to about a kilometre, and go only to Open-Meteo for the forecast. With no place name to look up, the first request isn’t made at all. If you refuse, nothing changes; you can still type a town.

Typed coordinates (such as 59.53, 18.08) are used as they are, so the first request isn’t made for them either: only the forecast request goes out, with the coordinates rounded to about a kilometre.

A return visit works differently. Your chosen location is kept in your own browser so you don’t have to type it again (it is also used by the gallery’s sky view), along with your telescope, sky, view and unit settings, and the page uses it as soon as it loads: it reads the target list from this site and asks Open-Meteo for the forecast for those coordinates, without waiting for you to press anything. That carries out the choice you made last time, but it does mean a request leaves your browser when the page loads. Clearing this site’s data removes the stored location, and the page goes back to asking.

The Nocturne NR plugin for Photoshop

The Photoshop plugin is a paid product with its own licence, so it has its own privacy page. That page covers what the plugin sends, and what the shop keeps when you buy it.

Questions, or a removal request

Nocturne is written by one person in Sweden. Ask me anything about this page, or ask me to delete something, at privacy@nocturneastro.com. For most of what is described here, nothing is stored that could be identified as yours, but ask and I will tell you exactly what there is.

For anything that is not about privacy — a bug, or a question about using Nocturne — please use the report form instead. It reaches me the same way, and it arrives with the version and log that usually make the difference between a fix and a round of questions.