In previous article, I mentioned Best Free Clockify Alternative but now in this article, I have mentioned best free (open-source) or paid SonarQube Alternatives which can be helpful to review code.

SonarQube is an open-source code review tool used to analyze and review code quality. Like every human, developers are capable of making mistakes when coding, and they need a good code review tool like SonarQube to find errors, fix them, and know their effects and the statistics regarding these errors.

SonarQube has two plans; the free "Community Edition" and the paid "Premium Edition;" Both plans support different programming languages.

However, you may want to try out free alternatives to SonarQube, especially if you want a free code review tool that supports languages like C/C++, COBOL, Objective-C, PL/SQL, and others.

Here are some of the free code review tools that you could use instead of SonarQube:

1. Codacy


Codacy is an automated code review tool used by developers and organizations for improving code quality and monitoring technical debt. With Codacy, you can save hours of code development daily because it reviews codes in every pull and commits request.

Features Of Codacy

  • Freemium
  • Open source
  • Easy to set up and customize
  • Better at support
  • Great user interface

2. Shellcheck


Shellcheck is an open-source code review tool that automatically checks for bugs in your shell scripts. It points out errors in shell scripts, explains why they occur and gives suggestions on how you can fix these errors.

Shellcheck is a worthy free alternative to SonarQube.

Features Of Shellcheck

  • Free
  • Open source
  • Can be an integrated linter in editors
  • Written in Haskell 
  • Easily added to builds or test suits

3. Cppcheck


Cppcheck is a free code analysis tool for C and C++ programming languages. It detects the type of bugs that compilers do not detect, but unlike many other analysis tools, it does not detect syntax errors in the code. The main goal of Cppcheck is to ensure you have very few false positives.

Features Of Cppcheck

  • Free
  • Open source
  • Checks for memory leaks
  • Out of bounds checking
  • Code checking for each class
  • It alerts you when you use obsolete functions.

4. Code Climate

code climate.jpg

Code Climate is a web-hosted software that is used to check code quality. It efficiently checks billions of lines of code weekly and deciphers errors.

Organizations prioritize using Code Climate because of its "Teams" feature, which allows these organizations to manage their teams.

Features Of Code Climate

  • Freemium
  • Nice user interface
  • Allows you to test the coverage of a range of new codes
  • Integrate easily with GitHub
  • It helps you track the progress of your codes

5. Flawfinder


Flawfinder is a code review tool for C and C++ programming languages and gives you a report on flaws that could compromise your code. Many programmers trust Flawfinder when they want to examine their software for potential security risks before it is released to the public.

This free code review tool not only identifies these security risks but also gives a report on them and lets you know how harmful they are. 

Features Of Flawfinder

  • Free
  • Open source
  • Easy to install and use

6. DeepSource


DeepSource is an automated code quality tool to monitor codes and detect potential issues. What DeepSource does is continuously analyze changes to source code to find and fix issues. These issues are security, bug risks, anti-patterns, and performance issues.

Companies that develop code review tools use static analysis to improve code quality. However, the developers of DeepSource have taken a step farther than others by adding extra layers of static analysis to make results more usable for developers.

Features Of DeepSource

  • Freemium
  • Easy to set up
  • Automatically run on every commit and pull request
  • A central hub for management of the team's code
  • Easily integrated with GitHub, GitLab, Bitbucket, and others

7. Coverity Scan

Coverity Scan.png

Coverity Scan allows you to find defects and fix them for free in your Java, C/C++, or C# open source projects. This code review tool tests each line of code and the potential execution path to find defects. If they are found, it gives a well-detailed explanation of the cause so you can fix it quickly.

Features Of Coverity Scan

  • Freemium
  • Easy to use
  • Fully customizable 
  • It supports over 22 languages
  • It does not lose its functionality when switching between languages
  • Debug codes faster


SonarQube is a good code review tool, but you should check out the alternatives we have discussed in this article. You may find a new favorite tool for code quality.

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