Online Tools

Utilities or programs which can be run online without any need of installation or download.

Summary of sub-pages in this category

Finder Chart Tool

Finder chart

This is a simple tool for generating pretty, shareable and interactive Finder Charts using Aladin Lite. The interface provides a quick access to a bunch of links for various useful online tools and resources, including our object visibility plotter.

You may link or embed this tool in your...

Object Visibility Plotter

Object Visibility Plotter

This tool plots the airmass (and altitude values) for an object or a list of objects given its RA and Dec for any given date. See demos: Single Object, Multiple objects, Demo3. Additional features include:

  • Can plot a single object or a list of objects with their names and corordinates...
Online Photometry Tool

Photometry tool

This online program is for doing quick and easy Photometry of Astronomical images and get the magnitude of a point source. See a demo output here.

  • Using the tools is as simple as just to provide the Image file and RA-Dec of the desired source. That's all, you get the calibrated magnitude...

Error Propagation Calculator

Error Propagation Calculator

This application calculates error (uncertainty) propagation for any given arbitrary analytical function. It derives an analytical expression of the error propagation relation. It can also calculate numerical value of the function and its error if values are provided for input variables. See a d...

Sidereal Clock

Sidereal Clock

This tool calculates the local sidereal time for a given longitude and shows the time running in real-time. Sidereal and solar times are shown in both local and Greenwich time.

See a demo here.

You may either use the tool from below or open it in an external window. You can share or bookm...

Astronomy Calculator

Online Console Calculator

An online command-line calculator with built-in astrophysics-related functions, units, constants, and datasets. This calculator supports complex calculations involving expressions with units and variables. Inline plotting is also supported. It is a fully capable general-purpose calculator as wel...

Miscellaneous and Old Tools

Here some old tools / pograms are listed which are no longer actively maintained.

Graph Plotter


This is an old graph plotting tool built sometime around year 2005, when online plotting tools were non-existent (to my knowledge). The output plot is generated purely in PHP from scratch, utilizing pixel-by-pixel basic line drawing capability without using any plotting package or 3rd party ut...

Online Latex Renderer

Latex Renderer

This is an old tool for online rendering Latex commands. It was built when online rendering of Latex was not a thing (AFIK).

Latex is rendered and displayed using Cgi and PHP scripts. The tool also provide a GUI for easy insertion of Latex symbols and components.

Launch Latex rendering app...