UMLet - UML Tool for Fast UML Diagrams

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2023-03 (4.27), 2022-12 (4.26), 2022-09 (4.25), 2022-06 (4.24), 2022-03 (4.23), 2021-12 (4.22), 2021-09 (4.21), 2021-06 (4.20), 2021-03 (4.19), 2020-12 (4.18), 2020-09 (4.17), 2020-06 (4.16), 2020-03 (4.15), 2019-12 (4.14), 2019-09 (4.13), 2019-06 (4.12), 2019-03 (4.11), 2018-12 (4.10), 2018-09 (4.9), Photon (4.8), Oxygen (4.7), Neon (4.6), Mars (4.5), 2023-06 (4.28), 2023-09 (4.29), 2023-12 (4.30), 2024-03 (4.31), 2024-06 (4.32), 2024-06 (4.33)

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Solution Description

The free UML tool UMLet lets you draw UML diagrams with a light-weight, pop-up-free user interface. It lets you draw diagram sketches fast; export diagrams to pdf, eps, jpg, gif, svg, bmp, png, and system clipboard; share diagrams using Eclipse 3+; and create your own custom graphical elements.

Additional Details

Eclipse Versions: 2023-03 (4.27), 2022-12 (4.26), 2022-09 (4.25), 2022-06 (4.24), 2022-03 (4.23), 2021-12 (4.22), 2021-09 (4.21), 2021-06 (4.20), 2021-03 (4.19), 2020-12 (4.18), 2020-09 (4.17), 2020-06 (4.16), 2020-03 (4.15), 2019-12 (4.14), 2019-09 (4.13), 2019-06 (4.12), 2019-03 (4.11), 2018-12 (4.10), 2018-09 (4.9), Photon (4.8), Oxygen (4.7), Neon (4.6), Mars (4.5), 2023-06 (4.28), 2023-09 (4.29), 2023-12 (4.30), 2024-03 (4.31), 2024-06 (4.32), 2024-06 (4.33)

Platform Support: Windows, Mac, Linux/GTK

Organization Name: The UMLet Team

Development Status: Production/Stable

Date Created: Saturday, November 5, 2005 - 23:50

License: GPL

Date Updated: Friday, October 6, 2023 - 10:50

Submitted by: UMLet Team

Date Ranking Installs Clickthroughs
July 2024 52/653 459 18
June 2024 48/681 782 25
May 2024 37/682 1104 38
April 2024 41/687 1093 28
March 2024 50/694 877 28
February 2024 49/687 730 17
January 2024 50/691 814 29
December 2023 33/671 1200 30
November 2023 36/686 1251 36
October 2023 34/673 1471 45
September 2023 49/663 900 27
August 2023 60/673 643 21
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Unsuccessful Installs

Unsuccessful Installs in the last 7 Days: 1

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Marketplace Drag to Install Button

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Drag to your running Eclipse* workspace. *Requires Eclipse Marketplace Client

Reviews Add new review

A very easy to use tool to create all kinds of UML, I have not had any issues with it so far. Overall, 10 out of 10

<p>I LOVE the Standalone version. When you get the hang of scripting on the (THX GOD) ONLY properties box, UML goes so fast. And great simple click and drag, no need of thousands of link and fill montrous properties like EA when all you want is to drag an arrow around... Somethings are just needed as KISS. This is for those who think UML is one of those, specially on huge buroucratic companies at a new project pre-analysis phase, where you just throw some note, include different Areas to ask for new APIs in a note in an arrow, and so on...</p>

UML generation crashes when encountering a java enum.   

Found an open issue from 2016 - umlet github issue 352 - no java enum support (sorry can't post link as it's not allowed).    So if you want to use this tool to generate UML from existing source code and your project contains enums, its a no go.

I have problem with UMLet, right clicking on the background of the diagram causes the eclipse to crash

Im using Eclipse IDE for Java Developers Version: 2021-03 (4.19.0)
openjdk 11.0.10 2021-01-19 on ubuntu 20.04

You can¨t work with this in current Eclipse. Hopefully you could at some point. Uninstalling this time-waster.

I love it! Perfect for this modern agile age, when productivity is measured through working code - not diagrams. UML is just for easy human communication, just outlining some points, it should take minutes (sometimes seconds), and that's exactly what UMLet is providing. Thanks :)

I use UMLet about twice a year and have always liked it. But the current versio fails to install with:

An error occurred during the org.eclipse.equinox.internal.p2.engine.phases.CheckTrust phase.

In reply to by UMLet Team

Looking through the log, I found " Exception in opening zip file: /home/mnl/.p2/pool/plugins/com.umlet.plugin_14.3.0.jar". Copying the file manually to that location fixed the problem (i.e. after copying, I could install from marketplace).

Here's the full stacktrace:

!ENTRY org.eclipse.equinox.p2.engine 4 4 2020-02-25 12:30:25.452
!MESSAGE An error occurred during the org.eclipse.equinox.internal.p2.engine.phases.CheckTrust phase.
!SUBENTRY 1 org.eclipse.equinox.p2.engine 4 0 2020-02-25 12:30:25.452
!MESSAGE session context was:(profile=_home_mnl_tools_eclipse-latest_eclipse, phase=org.eclipse.equinox.internal.p2.engine.phases.CheckTrust, operand=, action=).
!SUBENTRY 1 org.eclipse.equinox.p2.engine 4 0 2020-02-25 12:30:25.452
!MESSAGE Error reading signed content.
!STACK 0 Exception in opening zip file: /home/mnl/.p2/pool/plugins/com.umlet.plugin_14.3.0.jar
    at org.eclipse.osgi.framework.util.SecureAction.getZipFile(
    at org.eclipse.osgi.internal.signedcontent.SignedBundleHook.getSignedContent(
    at org.eclipse.equinox.internal.p2.engine.phases.CertificateChecker.checkCertificates(
    at org.eclipse.equinox.internal.p2.engine.phases.CertificateChecker.start(
    at org.eclipse.equinox.internal.p2.engine.phases.CheckTrust.completePhase(
    at org.eclipse.equinox.internal.p2.engine.Phase.postPerform(
    at org.eclipse.equinox.internal.p2.engine.Phase.perform(
    at org.eclipse.equinox.internal.p2.engine.PhaseSet.perform(
    at org.eclipse.equinox.internal.p2.engine.Engine.perform(
    at org.eclipse.equinox.internal.p2.engine.Engine.perform(
    at org.eclipse.equinox.p2.operations.ProvisioningSession.performProvisioningPlan(
    at org.eclipse.equinox.p2.operations.ProfileModificationJob.runModal(
Caused by: java.nio.file.NoSuchFileException: /home/mnl/.p2/pool/plugins/com.umlet.plugin_14.3.0.jar
    at java.base/sun.nio.fs.UnixException.translateToIOException(
    at java.base/sun.nio.fs.UnixException.rethrowAsIOException(
    at java.base/sun.nio.fs.UnixException.rethrowAsIOException(
    at java.base/sun.nio.fs.UnixFileAttributeViews$Basic.readAttributes(
    at java.base/sun.nio.fs.UnixFileSystemProvider.readAttributes(
    at java.base/sun.nio.fs.LinuxFileSystemProvider.readAttributes(
    at java.base/java.nio.file.Files.readAttributes(
    at java.base/$Source.get(
    at java.base/$CleanableResource.<init>(
    at java.base/$CleanableResource.get(
    at java.base/<init>(
    at java.base/<init>(
    at java.base/<init>(
    at org.eclipse.osgi.framework.util.SecureAction.getZipFile(
    ... 13 more


I work for a large contractor doing air traffic control work for the FAA.  We are lookijng at using this tool (I am evaluatiing), but we would want some kind of paid support.  Do you all have maintenance/support contracts?

Thanks for your great tool.

Running Ubuntu 19.04 on Lenovo Yoga 530 AMD Ryzen 7 laptop.

Using UMLet from within Eclipse and right clicking on a diagram makes Eclipse crash.  Any ideas? 

Eclipse IDE for Java Developers
Version: 2019-03 (4.11.0)
Build id: 20190314-1200
OS: Linux, v.5.0.0-20-generic, x86_64 / gtk 3.24.8
Java version: 11.0.3

Just started to use UMLet to design a music-related database-driven application in Lazarus free pascal.  I am very impressed with UMLet's intuitive user interface.  It has enabled me to generate a suite of class diagrams at several levels of detail which exactly fit my needs. 

I am Macos Mojave user. Initially I downloaded the file, unziped and copied the com.umlet plugin version 14.3 jar file to the Eclipse plugins area but it did not work then tried to place in the p2 but it did not work.. After many attempts, I managed to install UMLet uml tool fast uml diagrams as suggested in marketplace and it worked. I created a Use Case diagram and saved it and closed Eclipse. I reopened Eclipse and tried to access my use case diagram and it hanged Eclipse and I had to force Eclipse closed. This hangs the Eclipse every time. I don't know what to do now as this is for my programming course in Australia. I have access to the error logs and I can send it if needed. 

In reply to by Mei Chee

Hi -- sorry to hear that, although unfort. we are not surprised.. First, it'd probably be best for you to use UMLet standalone on macOS, or if you only need very light-weight diagrams, the online version at

We are aware of an Eclipse plugin issue on macOS, but we have been unable to track it down, as the logs do not seem to point to the core issue here; we suppose it's an interplay with Swing. It usually happens with multiple UMLet windows open.

Sorry again!

The UMLet Team

This is a very nice software but full of bugs. On xubuntu 18.04 I crashed Eclipse 5 times in 30 minutes.Conclusion it is not usable for the moment

In reply to by Odile LAMBERT

Hi -- we develop and test the plugin variant of UMLet mostly on Eclipse & Windows. It's a bit tricky to also check for the myriads of other combinations. If you can reproduce the crash, could you please send the Eclipse log entries contained in your workspace's .metadata/.log to Thanks, The UMLet Team

I cannot get an editing cursor to appear in the lower right window where the attributes of a class are supposed to be edited. When I click on a line, I get a yellow line highlite, and no cursor. When I type nothing happens.

I am on a clean Oxygen install on OS X.

Not useable at this point.

In reply to by Michael Grouse


we'll try to replicate this; given the large # of combinations of OS, Eclipse versions, and Java versions, such issues are tricky to test comprehensively. OS X & latest Ecl version is always a hot candidate for some mess-up.

Feel also free to directly notify us of such bugs via email.


The UMLet Team


Fix these:
- no update url
- no drag-able install icon
- not listed in Eclipse integrated marketplace search

Why isn't there a strict rule for marketplace that requires any plugin listed here to provide these? Horrible user experience.

In reply to by dvd gsng

A few comments to outline our view on this..

We have implemented an install icon and released it about two months ago for a few days, but hit some compatibility issues. After a relatively quick check did not result in a fix, we abandoned this thread for the time being; we want to focus on the tool itself, instead of its surrounding infrastructure, as our time is limited. But no excuse here, we just stumbled over some technicality, and, being lazy, did really not enjoy digging in.

On a more general note, I personally am not a very big fan of this drive towards "user friendly" install overheads; I personally dislike installers in general; am not fond, e.g., of the "virtual drive downloads" on OS X for many tools (why the extra layer?); and am bothered by how many plugins seem to hide/forget their simple basic package downloads in favor of update sites/drag-and-drop buttons etc. As for the latter, if you use Eclipse over X-Windows, or Eclipse on a server farm without internet access, these "helpful" installation methods won't work, might send Eclipse (and other tools) into a non-stop and futile internet lookup; and require relying on the old school package download anyway -- if that way is neglected or unsupported, the whole exercise becomes excruciating fast. In short, in many instances I like to download what I want directly, and in the version I choose, and start it right away. But I am aware that that's a very personal take on all this, and largely gut-driven -- we will in fact look into install support down the line again, and hope to then put this to rest.

Try to download this for my Eclipse, but download button not available. It's also not possible to find the tool via the marketplace in Eclipse. How can I get this tool?

This tool is enough to make fast simple & nice documentation.
To install the plugin just drop the jar into the 'eclipse/plugins' folder.

This is an outstanding, lightweight tool for quick UML markup. This is the perfect tool for someone that is a developer, not a business analyst, and when just needs to quickly diagram some knowledge to add to a story or wiki.

I've used mostly Visio in the past but was looking for something open-source and Linux-friendly without all the bells and whistles, this is exactly what I needed.

Simplistic approach at UML designs and very light weight, loving it. Am using as stand alone without eclipse integration, it makes navigation and reference lookup on code very much comfortable.

I love the ease of making quick UML diagrams with this. Easy to use and customize elements and charts for you own purposes. There are however a few disadvantages that drive me nuts while trying to make quick diagrams on the fly:

- Line tools like the "has a" and "is a" always get copied behind to the back layer, this is EXTREMELY frustrating when trying to align new elements up. Why would you ever want to copy a new object to the back z index? You can right click and change the layer to bring it to the front, but this just destroys the whole flow and experience.

- Its a bit tricky to grab and move the smaller elements as the grab handle for elements is relatively small.

- It takes a bit of getting used to, but ctrl selecting is used to lasso objects where simple clicks move the screen around. I understand this is more of a preference but I find it much nicer to select lasso with a simple click and use the ctrl + mouse to move around.

- When double clicking on elements (this duplicates them), it sometimes places itself at the end of another line segment automatically attaching itself to that line or connector. This means I have to either copy and paste (Which can have the same effect depending on the area of the screen, forcing me to move the screen so that the upper left corner is free (where the new element gets pasted)) or create one from the elements palatte.

Other than that, I really do like how fast I can make beautiful custom UML diagrams with little effort!

4.5/5 :D

It will take a little to learn the fields you can add to the "properties" for each UML element but once you understand how it works it is so easy to get the job done!

Very nice piece of software. Easy to use, responsive, ideal for quick UML diagrams without having any code generation baggage behind it.