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Klogg is a multi-platform GUI application that helps browse and search through long and complex log files. It is designed with programmers and system administrators in mind and can be seen as a graphical, interactive combination of grep, less, and tail.

Klogg main window

Please refer to the documentation page for how to use Klogg.

Latest testing builds

Windows Linux Mac
continuous-win continuous-linux continuous-osx

Table of Contents

  1. About the Project
  2. Installation
  3. Building
  4. How to Get Help
  5. Contributing
  6. License
  7. Authors

About the Project

Klogg started as a fork of glogg - the fast, smart log explorer in 2016.

Since then it has evolved from fixing small annoying bugs to rewriting core components to make it faster and smarter that predecessor.

Development of klogg is driven by features my colleagues and I need to stay productive as well as feature requests from users on Github and in glogg mailing list.

Latest news about klogg development can be found at

Comparing with glogg

Klogg has all best features of glogg:

  • Runs on Unix-like systems, Windows and Mac thanks to Qt5
  • Is fast and reads the file directly from disk, without loading it into memory
  • Can operate on huge text files (10+ Gb is not a problem)
  • Search results are displayed separately from original file
  • Supports Perl-compatible regular expressions
  • Colorizes the log and search results
  • Displays a context view of where in the log the lines of interest are
  • Watches for file changes on disk and reloads it (kind of like tail)
  • Is open source, released under the GPL

And on top of that klogg:

  • Is heavily optimized using multi-threading and SIMD
  • Supports logical combinations of search patterns
  • Supports many common text encodings
  • Detects file encoding automatically using uchardet library (supports utf8, utf16, cp1251 and more)
  • Can limit search operations to some part of huge file
  • Allows to configure several highlighters sets and switch between them
  • Has a scratchpad window for taking notes and doing basic data transformations
  • Provides lots of small features that make life easier (closing tabs, copying file paths, favorite files menu, etc.)

Here is a small demo showing how much faster klogg is (searching in ~1Gb file stored on tmpfs):


List of glogg issues that have been fixed/implemented in klogg can be found here.

Prominent features of dev-builds compared to latest stable release:

  • support for files with more than 2147483647 lines
  • much faster regular expressions search (2-4 times)
  • ability to combine regular expressions with boolean operators (AND, OR, NOT)
  • configurable shortcuts
  • list of configurable predefined regular expression patterns
  • better dark mode
  • build scripts allow to use more dependencies from OS packages instead of vendored versions

List of all changes can be found here.

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This project uses Calendar Versioning. For a list of available versions, see the repository tag list.

Current stable release builds

Current release is 20.12. Binaries for all platforms can be downloaded from GitHub releases.



Windows installer is also available from Chocolatey:


Mac OS

Package for Mac can be installed from Homebrew

homebrew cask


It is recommended to use klogg package from distribution-specific repositories.

Generic packages are available from klogg DEB and RPM repositories hosted at JFrog Artifactory. They are built to run on Ubuntu 16.04 and Centos 8 (x86-64 only).

For DEB add klogg artifactory repository, then install from apt:

echo deb [trusted=yes] stable utils | sudo tee -a /etc/apt/sources.list
sudo apt-get update
sudo apt-get install klogg

For RPM create klogg repo file in /etc/yum.repos.d/klogg-rpm.repo with this content:


Then install using yum

sudo yum update
sudo yum install klogg

Testing builds

CI Build and Release

Windows Linux Mac
continuous-win continuous-linux continuous-osx

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Please review for how to setup Klogg on your local machine for development and testing purposes.

How to Get Help

First, please refer to the documentation page.

You can open issues using klogg issues page or post questions to glogg development mailing list.


We encourage public contributions! Please review for details on our code of conduct and development process.


This project is licensed under the GPLv3 or later - see COPYING file for details.


See also the list of contributors who participated in this project.

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