Aladin Lite

A lightweight sky atlas running in the browser

Aladin lite is a lightweight version of the Aladin Sky Atlas, running in the browser and geared towards simple visualization of a sky region.

It allows one to visualize image surveys (JPEG multi-resolution HEALPix all-sky surveys) and superimpose tabular (VOTable) and footprints (STC-S) data.

Aladin lite is powered by the WebGL, supported by all modern browsers

Aladin lite is easily embeddable on any web page and can also be controlled through a Javacript API.

It is dedicated to replace the Aladin Java applet technology in the medium term.

The panel on the right hand is not a regular image. It is actually Aladin Lite running as an embedded widget. You might try to zoom in and out using your mouse wheel, or pan the view to move around.

For more details and options, have a look at the tutorial Build an interactive sky map with Aladin Lite, initially developed for dotAstronomy7. Developers might also be interested in this tutorial, which shows step by step how to create an interactive sky map with Aladin Lite.

Aladin Lite v3 is out and comes with the following features:

  • WebGL2 new graphical engine
    • FITS HiPS tiles support and dynamic client-side cutouts changes
    • All-sky projections support: Aitoff, Mollweide, Azimuthal, Gnomonic, Mercator and many more
    • Multiple image survey overlays
  • Better MOC support
    • Can display MOCs up to max HEALPix order 29 (~0.4 milli-arcsecond HEALPix cells)
    • use of performant Rust librairies cds-moc and cds-healpix
  • New coordinate grid overlay - more customisations to come!
  • Smartphones/tablets enhanced experience: pinched rotation and zoom, move with inertia
  • Still lightweight (half a megabyte)
The code source is available on our repository at this link. This also provides a little snippet of code for you to have a minimal aladin lite v3 running into your webpages.

Please send us your feedback, comments, feature requests and bug reports to, they are very welcome.

A migration page intended to help users switching from the v2 to the v3 is available at this link

Aladin Lite comes with a full-featured API allowing one to customize its interface, control the view, change the image survey to display, create catalogues and overlay layers, develop powerful interactions between a web page and Aladin Lite.

The Aladin Lite API is described on a dedicated page.

Developers might also be interested in this tutorial, which shows step by step how to create an interactive sky map with Aladin Lite.

To give you an overview of how Aladin Lite can be used, have a look at the list of examples.

Aladin Lite has been integrated in the main CDS services:

  • On the SIMBAD page for an individual object, it provides an interactive preview image (see example for Messier 1).
  • The VizieR results page features a start Aladin Lite button to visualize the positions of listed sources (see example)

Outside CDS, Aladin Lite is used in several projects:

If your project is using Aladin Lite, we would be happy to have it listed here. Drop us a line!

Aladin Lite source code is available under GPL3 license and can be browsed from the CDS github repository

If you think this license might prevent you from using Aladin Lite in your pages/application/portal, please contact us.

For developers willing to self-host Aladin Lite on their own server, you can download all assets at this link.

ipyaladin is a Jupyter notebook widget, developed at CDS, and allowing for easy embedding and control of Aladin Lite from an IPython notebook.


Ladislav Heller (ladislav.heller at has integrated Aladin Lite in an Android application using the Xamarin framework.
His development is available in his github repository:


If you have integrated Aladin Lite in an iPhone application, please let us know.

This page features some experimental, original usages of Aladin Lite.

  • ALiX

    ALiX is a flexible catalog portal based on Aladin Lite. It it designed to use an interactive sky view as a primary selection tool. The ALiX view is constantly updated with data queried in the host database. It offers advanced functionalities allowing to mix local data with VO data. Users can plot by hand areas of interest and manage an historic of the views.

    ALiX has no dependency with any specific data source; it can be integrated in any existing portal.

  • Region editor

    The region editor is an Aladin Lite extension allowing users to plot polygons over the current sky view, and retrieve the coordinations of the vertices.
    It has been designed to be used as an interface for searches by region or for cutout services.
    This development has been funded by the SSC XXM-Newton.

    Documentation, installation instructions can be found on this page.

  • Tour navigator library

    The tour navigator is an Aladin Lite extension that allows to implement easily virtual tours of objects of interest. It has been designed to be used as interface for navigating through the sky from object to object. Allowing users to learn about each object they visit in the tour. The tour navigator plugin has been developed and designed at CEFCA (Centro de Estudios de Física del Cosmos de Aragón) by Tamara Civera. Documentation, source code and installation instructions can be found on this page.

January 2023

release of the v3

this features the support of a coo grid, multiple allsky projections, multiple image surveys overlays (as well as FITS HiPS), dynamical cuts, stretch and colormap change

February 2019

add method getViewWCS

bug fix for MOC rendering: MOC cells at order 0 and MOC with order>13 are now properly displayed

September 2018

drawing algorithm improvement: no more flickering when zooming in

mobile devices support: pinch to zoom works, panning works better

bug fix in VOTable parsing: CDATA text was always blank in TD tags

August 2018

bug fix for rectangular selection of sources (aladin.on('select', ...))

URL generated for a VizieR cone search now take into account the option 'limit', as to limit the size of the retrieved VOTable

April 2018

add Simbad pointer tool

add startup options realFullscreen and simbadPointer

add method zoomToFoV (zoom with animation)

improve rendering of all-sky view

add option showAllskyRing

December 2017

footprint selection is enabled (Fabrizio Giordano [ESA/ESDC] contribution)

add listener for 'mouseMove' event

add dragging attribute to positionChanged listener callback param

improve positionChanged listener: no more called when clicking on an object

support Circle when generating footprints from STC-S descriptions

Catalog.onClick can now also be a function

add function udpateShape for Catalog and ProgressiveCatalog object

add shape option 'circle' for catalogues

bug fix for progressive catalogues rendering

September 2017

fix: export PNG was not working any longer in latest version of Chrome, as top frame navigation to data URL was no longer allowed

improvement: MOCs, catalogs and overlays have now different logos in the "stack"

gotoObject: can now take a success callback function

dimensions can be specified for getViewDataURL method

add listener for 'click' event

improve MOC display speed

bug fix : MOC display with norder>9 (thanks to Raffaele D'Abrusco for the bug report)

Sesame bug fix when used in a local file web page

MOC display is way faster when panning

August 2017

add adaptativeDisplay option for MOCs

try first to load MOC through given URL, and only if it fails, try through proxy (allows to load local/not publicly accessible MOCs)

all graphical overlays (footprints, MOCs) in addition to catalogs are now visible and can be shown/hidden from the control panel

fix: when going full screen, background is now all white (no more HTML elements visible in the background)

style improvement: layer labels in Overlay layers panel are rounded at both ends

add J2000d option for frame selection

July 2017

MOC display bug fix

add method adjustFovForObject

add listeners on positionChanged and zoomChanged

Sesame call now done in HTTPS

February 2017

shape parameter when creating a catalogue can now be a custom draw function

bug fix for displaying a HiPS overlaid over a HiPs with a different coordinate frame

January 2017

new method allowing direct query to SkyBot

January 2017

new method allowing direct query to SkyBot

September 2016

support of HiPS catalog (new format)

June 2016

fix astrometry offset by subdividing HEALPix cells too distorted

new method A.MOCFromJSON to create a MOC from the JSON serialization

March 2016

added raField and decField options when creating catalogue

December 2015

added cubehelix color map

added option in A.catalogFromURL to bypass proxy

access to Simbad and VizieR data (catalogFromVizieR and catalogFromSimbad) are now done directly, without the proxy

Novembre 2015

new methods getShareURL and getEmbedCode

October 2015

new methods for easy retrieval of Simbad, NED and VizieR data

new options for Catalog.onClick: 'showTable' or 'showPopup'

December 2014

added displayLabel option for a catalog overlay

added lineWidth option for A.graphicOverlay objects

October 2014

New shapes available for catalogue sources

Various bug fixes

April 2014

New API methods: getSize, getFov, world2pix, pix2world, getFovCorners

November 2013

New features: progressive catalogues, color maps, fullScreen option at startup, PNG export

New API methods: setFOVRange, listeners on objectClicked, objectHovered

Bug fix: support for Firefox < 4

July 2013

Added zoom control to the UI

Added method to trigger object selection

May 2013

First public beta release

Users can still use it but no more development will be done on it. The Aladin Lite v2 documentation can be found at this link as well as its code source here

Aladin Lite v3 is in part supported by the ESCAPE project (the European Science Cluster of Astronomy & Particle Physics ESFRI Research Infrastructures) that has received funding from the European Union's Horizon 2020 research and innovation programme under the Grant Agreement n. 824064.
Aladin Lite v3 has also been supported by the Europlanet 2024 RI project that has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 871149.

Aladin Lite is developed and maintained by Thomas Boch and Matthieu Baumann

Send your feedback, comments, feature requests and bug reports to this email address.

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