What is ImageJ used for?

ImageJ is a Java-based public domain program for processing and analyzing scientific images, with a plugin ecosystem and many derivatives. It is a good fit for measuring features in microscopy images and embedding image analysis in Java projects.

Is ImageJ open source?

Yes. ImageJ is open source under a custom licence. Its source code is on GitHub at imagej/ImageJ and is written mainly in Java.

Yes. ImageJ is open source, so the software itself is free to use under the terms of its own licence.

Can I self-host ImageJ?

Yes. ImageJ can be self-hosted on your own server or infrastructure.

What are some alternatives to ImageJ?

Similar open-source tools in the Photos & Images category include 3D Slicer, Immich and PhotoPrism. SaaS products in the same category include imgix, 100xglow and 500px.

Is ImageJ actively maintained?

Yes. The most recent commit to ImageJ was on 22 July 2026. The project has 789 stars on GitHub.

ImageJ: open-source photos & images

About ImageJ

ImageJ is public domain software for processing and analyzing scientific images. It is written in Java, which lets it run on many different platforms. The ImageJ website is the primary home of the project, and a community-built wiki documents it along with derivatives and flavors such as ImageJ2 and Fiji.

For developers, ImageJ can also be used as a library: it is published on Maven Central from version 1.48r onward and in the SciJava Maven repository for earlier versions. The README advises that versions before 1.53k may not match the release tags in the repository exactly. Building from source is recommended with OpenJDK 8 or 11, using either Apache Ant or Maven, because newer Java versions are not yet supported.

Community help is available through an ImageJ mailing list and the Image.sc Forum, and the wiki has a contributing page for people who want to help. Topics on the repository highlight image processing and computer vision.

Key features

Processing and analysis of scientific images
Cross-platform Java application
Usable as a library through Maven
Related ImageJ2 and Fiji distributions
Builds with Ant or Maven

Good fit for

→Measuring features in microscopy images
→Embedding image analysis in Java projects

Built with: Java
Tags: image-processing; scientific-imaging; java; computer-vision; public-domain; image-analysis; fiji

ImageJ: questions and answers

What is ImageJ used for?: ImageJ is a Java-based public domain program for processing and analyzing scientific images, with a plugin ecosystem and many derivatives. It is a good fit for measuring features in microscopy images and embedding image analysis in Java projects.
Is ImageJ open source?: Yes. ImageJ is open source under a custom licence. Its source code is on GitHub at imagej/ImageJ and is written mainly in Java.
Is ImageJ free?: Yes. ImageJ is open source, so the software itself is free to use under the terms of its own licence.
Can I self-host ImageJ?: Yes. ImageJ can be self-hosted on your own server or infrastructure.
What are some alternatives to ImageJ?: Similar open-source tools in the Photos & Images category include 3D Slicer, Immich and PhotoPrism. SaaS products in the same category include imgix, 100xglow and 500px.
Is ImageJ actively maintained?: Yes. The most recent commit to ImageJ was on 22 July 2026. The project has 789 stars on GitHub.