A better finish for a night well spent
Star trails without the airplanes.
Bring your RAW or JPEG sequence. Close the gaps, clean up passing aircraft and shape the trails into a photograph worth keeping. Review every change before you export.
RAW · JPEG · TIFF · FITS →Free, no uploads
- Lines out before stackingEach frame is checked against its neighbours for passing aircraft and satellites.
- Six focused modesOnly the mode you choose is shown and run.
- Ready for your editor16-bit pictures and signed FITS where the mode supports them.
Same 50 frames · same brightness · shown at 200%
Continuous, even up close
A trail, not a dotted line.
The sky keeps moving while your camera pauses. Close those gaps along each star’s own arc, using the light you actually captured.
- Timing from your frames. Exposure and interval guide the repair.
- Adjust the amount. Keep the look you want, from a light touch to continuous trails.
- Inspect at full size. Here, each 20-second exposure was followed by an 11-second gap.
Frames: MobilTelesco: A Smartphone based Astrophotography Dataset, Shantanusinh Parmar (2025), CC BY 4.0. Stacked with this tool. Only gap filling changes; both sides use the same brightness settings and crop, shown at 200% without smoothing.
Keep the night. Lose the distractions.
Aircraft cross your sky.
They needn’t cross your picture.
Repair moving lines with the same patch of sky from neighbouring frames. Your stars keep their paths.
- Review each removal. See every candidate in its original frame, then stack again with your choices.
- Keep the moments that matter. Protect a meteor or any line you want to include.
- Check the actual difference. These 380 frames were stacked twice with only line removal changed.
Six kinds of night
One app for the whole night.
Explore the six modes → See real examples →From long star trails to a sharp planetary frame, choose a mode for the result you want.
From the first frame to the final edit
Make more of the night you captured.
Explore every feature →Keep the meteor
It finds straight lines; you choose what stays, so a meteor can stay. Restack with your choices.
See how review works →Give the trails your look
Choose from eight blends. Even out the background, make a softer average or taper both ends with Javelin.
Open Star trails →A picture, master or film
Keep editing with a 16-bit PNG, or choose TIFF for Star trails and Nightscape. Supported astro modes also write signed FITS. Star trails can also make a time-lapse video (MP4).
Choose an export →- 01
Choose your frames
Pick your result, then add its Lights, calibration files and masks.
- 02
Check the night
Review camera, dimensions and compatibility before decoding. Check a resource plan for this device.
- 03
Shape the recipe
Start with the defaults, then open just the groups you want to change.
- 04
Press Start
Follow preparation, survey and the build. Processing happens on your device.
- 05
Review and export
Inspect detail, keep or remove lines, then save the finished picture or film.
Visible difference
Your night, without what got in the way.
Open the gallery →
From camera to editor
Bring the files you already shoot.
Check your format →Camera RAW
ARWCR2 / CR3NEFDNGRAFORFRW2PEF
Pictures
JPEGPNGTIFFWebP
Astro & video
FITSSERAVIMP4 / MOV
Camera and video support varies. Check your format before a run.
Plans after the beta
Open to everyone while the beta is running.
See plans →Free
$0- 3 finished nights a month, shared between Star trails and Nightscape
- A 12-frame preview in Deep sky, Comet, Planetary and Calibration lab
- Line removal with review, gap filling, the evened sky and 16-bit PNG
- Every planning tool, map and aurora page
Pro
$5.99 a month$39 a year · save 46%
- Unlimited nights in all six modes
- 32-bit FITS masters, the time-lapse video (MP4) and cover images
- Resume a stopped run and stack a night in sections
- Desktop apps for macOS, Windows and Linux when they ship
Not open yet — nothing is charged, and no card is asked for. All modes and exports stay open during the beta.
Before your first night
A few things worth knowing.
Bring the photographs you want to work on. Every mode is open while the beta runs.
Where do my photographs go?
They stay on this device. The browser reads and processes your selected files locally; it does not upload them for stacking. Read the privacy details.
Do I need to install anything or sign in?
No. Open the workspace in your browser, choose a mode and add your files. Processing begins when you press Start.
Can I use my phone?
Yes. A phone or tablet has less memory than a computer, so a night that does not fit at full size is made at a smaller picture size, and the plan beside Start says the size before anything is decoded. So far this has been tested by imitating an iPhone on a computer; measurements on real phones and tablets are still to come.
Will it remove a meteor?
The detector finds moving lines; it does not identify meteors. Review the candidates and choose Keep for anything you want in the picture, then restack with your choices.
Can I keep editing the result?
Save the 16-bit PNG to continue in a photo editor. Deep sky and other supported astro modes also provide FITS. The export sheet lists only the files your run actually produced. Choose the right file for your editor.
Plan before dark
Four planning tools. Nothing to install.
All planning tools →
Learn one thing at a time
Practical guides for the next clear night.
All guides →
Your first star trailCapture, stack and finish a complete night.Read →
Remove aircraft and satellitesWhat is detected, what is repaired and what stays reviewable.Read →
Formats that really workWhich RAW, FITS, SER, AVI and MP4/MOV files have been tested, and which are refused by name.Read →
Star trails on a MacA fair comparison with the desktop alternatives.Read →