Best Free Debugging Tools of 2026

Bugfender serves as a remote logger, crash reporting tool, and platform for in-app user feedback specifically designed for application developers. It captures every action within the app, even in instances where it doesn’t crash, allowing developers to replicate and address issues more efficiently, thus enhancing customer support. With a strong emphasis on user privacy, Bugfender operates efficiently in terms of battery and network usage, maintaining logging capabilities even when the device is offline. This tool empowers developers to identify and rectify bugs before users become aware of them. By logging bugs across all devices and delivering the results in mere seconds, Bugfender allows for prompt fixes, ensuring that users never encounter an error message. This proactive approach helps in achieving 5-Star Ratings. Beyond merely tracking crashes and bugs, Bugfender gathers comprehensive data essential for creating a detailed understanding of user behavior, which is vital for obtaining those coveted five-star ratings. Additionally, it facilitates exceptional customer service by enabling developers to focus on individual users, thereby offering tailored support to enhance user satisfaction and loyalty. Ultimately, Bugfender transforms the way developers interact with their applications and users, fostering a more resilient and user-friendly product.

Scout Monitoring is Application Performance Monitoring that shows you what charts cannot. Scout APM is an application performance monitoring tool that helps developers identify and fix performance problems before customers even see them. Scout APM's real-time alerting system, developer-centric interface, and tracing logic, which ties bottlenecks to source code directly, helps you spend less time on debugging, and more time creating great products. With an agent that instrument the dependencies needed at a fraction the overhead, you can quickly identify, prioritize and resolve performance issues - memory bloats, N+1 queries and slow database queries. Scout APM monitors Ruby, PHP and Python applications.

Xcode is a comprehensive development platform designed specifically for Apple ecosystem applications. It enables developers to build apps for iOS, macOS, watchOS, tvOS, and visionOS efficiently. Intelligent code completion adapts to your project and coding style. Xcode integrates powerful debugging and profiling tools to uncover performance bottlenecks. Live previews allow developers to visualize UI changes instantly while coding. Built-in simulators replicate real-device behavior for testing across multiple configurations. Automated testing frameworks help catch bugs early in development. Xcode Cloud adds continuous integration and delivery directly into the workflow. Developers can analyze real-world performance data from users. Xcode accelerates app development while maintaining high quality and reliability.

Bugsnag provides comprehensive monitoring of application stability, empowering teams to make informed choices about whether to prioritize the development of new features or to address existing bugs. As a robust full-stack stability monitoring solution tailored for mobile applications, it offers advanced diagnostics that enable you to replicate any error effectively. With a user-friendly interface, you can manage all your applications seamlessly from a single dashboard. Bugsnag serves as a crucial metric for assessing app health, facilitating communication between product and engineering teams. Not every bug requires immediate attention, allowing you to concentrate on those that significantly impact your business. Its extensible libraries come with well-considered defaults and a plethora of customization options. Additionally, the team comprises subject matter experts who are genuinely invested in minimizing errors and ensuring the overall health of your applications, making Bugsnag an invaluable asset for developers.

Sentry is a comprehensive application monitoring solution that empowers development teams to maintain reliable, high-performing software throughout the development lifecycle. The platform automatically captures errors, performance bottlenecks, logs, traces, user session data, and infrastructure insights, providing complete context for troubleshooting and optimization. With built-in AI capabilities such as Seer, Sentry helps engineers understand why failures occur, generate code fixes, and identify potential issues during code review. Integrations with popular development tools including GitHub, Slack, Jira, and Linear ensure that teams can monitor, investigate, and resolve issues without disrupting existing workflows.

Utilize Telerik Fiddler HTTP(S) proxy to capture all internet traffic between your computer and external sites, allowing you to analyze that traffic, set breakpoints, and manipulate both requests and responses. Fiddler Everywhere serves as a versatile web debugging proxy compatible with macOS, Windows, and Linux platforms. You can capture, inspect, and monitor all HTTP(S) communication, facilitating the mocking of requests and troubleshooting of network problems. This tool is applicable to any browser or application, enabling you to debug traffic across macOS, Windows, Linux, and mobile devices running iOS or Android. It guarantees that the necessary cookies, headers, and cache settings are properly exchanged between client and server. Supporting diverse frameworks such as .NET, Java, and Ruby, Fiddler Everywhere empowers you to mock or alter requests and responses on any website efficiently. This straightforward approach allows for testing website functionality without the need for code alterations. By employing Fiddler Everywhere, you can effectively log and analyze all HTTP/S traffic between your system and the wider internet, streamlining your debugging process.

You can easily scan through traffic by highlighting content type, status, and source. Or, you can use powerful filtering tools that match your messages to the most important ones. With MDN inline explanations and docs, you can examine the URL, status, headers, and body of each request, or response. You can explore message bodies using highlighting and auto formatting for JSON HTML, JS, JS and other formats, all with the help of Monaco, the editor in Visual Studio Code. Match requests precisely, jump to them as they appear, and edit any information: the target URL or method, headers, body, or method. You can either respond manually to the requests as they arrive or pass them upstream. On the way back, pause and edit the actual response. Step through HTTP traffic request-by-request, or manually mock errors and endpoints. To quickly prototype against new services or endpoints, create rules that match requests.

Ambassador Edge Stack, a Kubernetes-native API Gateway, provides simplicity, security, and scalability for some of the largest Kubernetes infrastructures in the world. Ambassador Edge Stack makes it easy to secure microservices with a complete set of security functionality including automatic TLS, authentication and rate limiting. WAF integration is also available. Fine-grained access control is also possible. The API Gateway is a Kubernetes-based ingress controller that supports a wide range of protocols, including gRPC, gRPC Web, TLS termination, and traffic management controls to ensure resource availability.

PlatformIO is an innovative collaborative platform designed specifically for embedded development, allowing users to conserve both time and resources by significantly lowering the costs and effort needed for software creation and maintenance. The embedded systems sector is in dire need of a transformative approach, as many existing IDEs and tools rely on outdated technology from the 1990s, presenting intricate requirements and platform-specific configurations that discourage skilled developers from pursuing careers in embedded engineering. Recognized as the most favored IDE solution for Microsoft Visual Studio Code, it offers a user-friendly and highly extensible integrated development environment equipped with a comprehensive suite of professional development tools. These tools are engineered to enhance both the speed and simplicity of embedded product creation and delivery. Additionally, PlatformIO is crafted entirely in pure Python, ensuring that it operates independently of any external libraries or system tools, which further streamlines the development process and fosters a more efficient workflow. Its commitment to modernizing embedded development makes it an essential choice for developers looking to innovate in this space.

Proactively discover, predict, and resolve errors with the continuous code improvement platform.

Easily monitor and manage application errors in just a few minutes using Airbrake, a powerful solution for error detection and monitoring. This efficient tool allows users to swiftly pinpoint, evaluate, and rectify issues, providing insights into parameters, stack traces, impacted users, and additional details. With its comprehensive dashboards, Airbrake simplifies error tracking and management significantly. Moreover, users can access Airbrake through its mobile-optimized web application, ensuring that they can stay informed and address issues on-the-go. This flexibility enhances the overall user experience and contributes to faster resolution times.

You can use your favorite debugging software to locally troubleshoot your Kubernetes services. Telepresence, an open-source tool, allows you to run one service locally and connect it to a remote Kubernetes cluster. Telepresence was initially developed by Ambassador Labs, which creates open-source development tools for Kubernetes such as Ambassador and Forge. We welcome all contributions from the community. You can help us by submitting an issue, pull request or reporting a bug. Join our active Slack group to ask questions or inquire about paid support plans. Telepresence is currently under active development. Register to receive updates and announcements. You can quickly debug locally without waiting for a container to be built/push/deployed. Ability to use their favorite local tools such as debugger, IDE, etc. Ability to run large-scale programs that aren't possible locally.

Open-source and free to use, this tool is compatible across various platforms and caters to all EVM blockchains. The Solidity Debugger Pro (sdbg) is an extension for VS Code that enhances the debugging experience for Solidity projects with a plethora of features. It accommodates all EVM-compatible blockchains, making it simple for developers to debug their smart contracts either locally or through a forked node. Additionally, sdbg offers integrated debugging support specifically designed for the widely-used Hardhat framework, ensuring a seamless development process. With its robust capabilities, sdbg significantly improves the efficiency of debugging in Solidity projects.

Errsole is a free open-source logger for Node.js applications. It comes with a built-in log viewer to view, filter, and search your application logs. 1) Minimal Setup: Just include the Errsole package in your code—no need for dedicated servers, software installations, or complicated configurations. 2) Logger++: Errsole automatically collects all logs from the Node.js console. Additionally, it provides advanced logging functions that support multiple log levels and the ability to attach metadata to logs. 3) Store Anywhere: Store your logs wherever you want—whether in a file or any database of your choice. You can also configure log rotation to specify how long logs should be retained. 4) Log Viewer: View, filter, and search through your logs using the built-in Web Dashboard. Secure authentication and team management features ensure that only you and your team can access the logs. 5) Critical Error Notifications: Get immediate notifications when your app crashes or encounters critical errors. The notification includes the error message, the app name, the environment, the server name, and a direct link to view the error in your logs.

With Bugsee, you can access videos, network activity, and logs that pinpoint the source of bugs and crashes in your live applications, eliminating the hassle of trying to reproduce sporadic issues. This tool ensures that all essential data is readily available, providing vital traces from your app to identify the root causes of unexpected behavior. You can view recordings of user interactions, backend communications, and system states that contributed to the issues. Additionally, Bugsee offers statistics on recurring crashes while also allowing you to analyze trends categorized by device type, operating system version, and time. You'll receive detailed information, including the specific filename, method, and line number associated with the crash. Furthermore, you can examine the states of all other threads active during the incident and review all HTTP and HTTPS requests and responses—complete with headers and body content—between your app and the server. The platform even allows you to replay all console logs from your app, perfectly synchronized with the video and network data, giving you a comprehensive view of the situation. This functionality ultimately empowers developers to enhance their applications with greater efficiency and precision.

RubyMotion allows you to swiftly create native applications for iOS, Android, and OS X, utilizing your preferred editor along with the beloved Ruby programming language. It incorporates a statically-compiled variant of Ruby tailored for mobile platforms and offers a command-line extensible toolchain that enables you to personalize your development process to suit your preferences. With RubyMotion, Ruby developers can start building iOS and Android applications immediately. This approach not only enhances the joy and productivity of programmers, but it also facilitates code reuse across platforms, ultimately leading to significant time savings and quicker project deliveries. Moreover, by maintaining a consistent language environment, teams can ensure smoother collaboration and streamlined development practices.

Thundra helps application teams to develop, debug, test, and monitor modern microservices on the cloud. By offering everything from automated instrumentation to cloud app debugging and test optimization in a single platform, Thundra eliminates the need for multiple tools for pre-production & production environments. Thundra offers 2 products: Thundra Foresight, to help you monitor & troubleshoot your CI workflows & tests. The second product is Thundra APM, which is an application performance monitoring for serverless and containers.

Elevate your log management with Honeycomb, a platform designed specifically for contemporary development teams aiming to gain insights into application performance while enhancing log management capabilities. With Honeycomb’s rapid query functionality, you can uncover hidden issues across your system’s logs, metrics, and traces, utilizing interactive charts that provide an in-depth analysis of raw data that boasts high cardinality. You can set up Service Level Objectives (SLOs) that reflect user priorities, which helps in reducing unnecessary alerts and allows you to focus on what truly matters. By minimizing on-call responsibilities and speeding up code deployment, you can ensure customer satisfaction remains high. Identify the root causes of performance issues, optimize your code efficiently, and view your production environment in high resolution. Our SLOs will alert you when customers experience difficulties, enabling you to swiftly investigate the underlying problems—all from a single interface. Additionally, the Query Builder empowers you to dissect your data effortlessly, allowing you to visualize behavioral trends for both individual users and services, organized by various dimensions for enhanced analytical insights. This comprehensive approach ensures that your team can respond proactively to performance challenges while refining the overall user experience.

Development teams can utilize the Disbug Chrome extension to effortlessly document bugs through screen recordings, screenshots, console and network logs, as well as user interactions, all uploaded to their project management system with just one click! This tool provides a visual narrative of the issue, allowing developers to witness precisely what transpired at the moment of failure. With a single click, the entire context for bug reports is captured, enabling teams to quickly understand the problem from multiple perspectives by recording the full session. Additionally, it consolidates technical logs within your preferred tools, complete with links for detailed logs. Everything can be centralized in your issue trackers, ensuring seamless integration with the tools that you already use. When a bug is reported, tickets are automatically created in the pre-configured issue tracker, which accelerates the debugging process significantly. This results in greater clarity and facilitates easier development. Moreover, it can reduce bug reporting time by up to 60%, thereby streamlining the workflow for QA testers, developers, and project managers, all for less than the cost of a cup of coffee! By optimizing this process, teams can enhance productivity and focus more on delivering high-quality software.

Kaption stands out as the premier analytics and feedback platform driven by artificial intelligence, specifically designed for digital marketers. Gain the critical insights necessary to enhance your digital presence and propel your business forward. By removing uncertainty, you can understand the reasons behind user behavior and iterate your strategies at a much quicker pace. One of the most effective ways to influence your audience is to perceive your offerings from their perspective. Have you considered how users navigate your website? With Kaption, you can map out the user journey and identify any obstacles encountered along the way. The path to excellence is paved with accurate information; without data, you are merely relying on luck or making mistakes. Direct your energies towards effective conversion and monitoring strategies. Take advantage of complimentary heatmap analytics to analyze user interaction with every component of your site and its impact on their actions. Identify where users face challenges, boost your conversion rates, and resolve product issues more swiftly with intelligent metadata insights. By doing so, you can ensure that your marketing efforts are both informed and effective.

Reports come to you instantly, automatically enriched with a wealth of valuable information, enabling you to address them fifty times quicker. Users can conveniently report a bug by simply shaking their phone, allowing them to provide feedback without exiting your app. When they perform the shake gesture, Shake activates, facilitating seamless communication of their issues. You can capture any data from the user's device that you require, and the .setMetadata() function allows for straightforward customization of this data according to your debugging needs. Additionally, you can track user interactions within your app, log custom events with .log(), and monitor all network activity before they submit a bug report to you. The web dashboard allows you to filter and locate specific bugs, such as those reported from iPad Airs that were in landscape mode while offline. You'll receive instant bug alerts in your team chat and can automate task creation directly in your preferred issue tracker. Shake is designed to integrate smoothly with the existing tools your team utilizes, enhancing productivity while ensuring that bug reporting is as efficient as possible. This streamlined process ultimately allows for quicker resolution of issues, improving the overall user experience.

Xdebug is a powerful PHP extension that enhances the development workflow by offering various tools and functionalities. It allows developers to step through code in their integrated development environment as scripts run, making debugging much easier. The extension provides an enhanced version of the var_dump() function and delivers stack traces for notices, warnings, errors, and exceptions, clearly indicating the path leading to issues. Additionally, it logs all function calls, including arguments and their locations, to the disk, and can be configured to also record every variable assignment and return value for each function. This feature set enables developers, with the aid of visualization tools, to thoroughly examine the performance of their PHP applications and identify any bottlenecks. Moreover, Xdebug reveals the sections of code that are executed during unit testing with PHPUnit, aiding in better test coverage. For convenience, installing Xdebug via a package manager is typically the quickest method; simply replace the PHP version with the version you are currently using. You can also install Xdebug using PECL on both Linux and macOS, utilizing Homebrew for a streamlined setup process. Overall, Xdebug significantly enhances PHP development by providing essential debugging tools and performance insights.

If you’ve ever taken a screenshot or recorded your screen, you’re already familiar with how to use Jam. Jam magically generates comprehensive bug reports containing all the essential information engineers require. It enhances bug reporting in any tool you prefer to utilize. You can easily share links to your bug reports or send them directly to your chosen issue tracker. Your teammates, regardless of whether they have signed up or not, can benefit from this tool. Jam gathers everything necessary for engineers to effectively troubleshoot issues. We have eliminated the need for those tedious follow-up calls to provide additional context, as all the required information is readily accessible. With Jam, you get perfectly crafted bug reports every time, minimizing unnecessary back and forth. It integrates seamlessly with your preferred issue trackers and tools, making it as straightforward as taking a screenshot. Trusted by countless teams across various companies, you can report bugs in mere seconds without interrupting your workflow. Currently, Jam assists developers during the code review and testing phases by capturing crucial bug diagnostic data and instantly replaying the issue, making it easier to pinpoint what needs fixing. This innovative approach not only saves time but also enhances collaboration among team members.

Polar Signals Cloud is a continuous profiling solution that operates continuously without the need for instrumentation, aimed at enhancing performance, comprehending incidents, and reducing infrastructure expenses. By executing a single command and following an exceptionally straightforward onboarding guide, you can commence cost savings and performance optimization for your infrastructure almost instantly. The capability to analyze past incidents allows users to trace and address issues effectively. The profiling data generated offers unparalleled insights into the execution of processes over time, enabling you to confidently identify the most critical areas for optimization based on statistical analysis. Many companies find that 20-30% of their resources are squandered on inefficient code paths that could be readily improved. By utilizing a remarkable combination of technologies, Polar Signals Cloud provides a profiling toolkit that meets the demands of modern infrastructure and applications. Thanks to its zero-instrumentation approach, you can implement it right away and start benefiting from actionable observability data that drives better decision-making. With ongoing use, organizations can continually refine their performance strategies and maximize resource allocation.

Effortlessly identify bugs and UI/UX inconsistencies with automation. The process of locating bugs can be both tedious and repetitive, but Buglab simplifies it by streamlining the testing of websites, platforms, and web applications. This tool accelerates development while maintaining high standards of quality for client-facing software, allowing you to prioritize other critical areas of your business. By catching UI bugs early, you can avoid costly repercussions. Buglab transforms website testing by enabling the simulation of various user actions with minimal clicks, all without requiring any coding skills. You have the flexibility to design any sequence of actions to confirm that modifications to your website do not introduce new bugs or alter existing functionality. After establishing a test, the system will provide results and clearly indicate any discrepancies between the original and updated versions of your site. You can also organize your tests into logical suites and projects, allowing for customized scheduling to fit your needs. Additionally, this approach enhances collaboration among team members, making it easier to track progress and ensure comprehensive coverage in testing.