Best Free Debugging Tools

Scout Monitoring is Application Performance Monitoring (APM) that finds what you can't see in charts. Scout APM is application performance monitoring that streamlines troubleshooting by helping developers find and fix performance issues before customers ever see them. With real-time alerting, a developer-centric UI, and tracing logic that ties bottlenecks directly to source code, Scout APM helps you spend less time debugging and more time building a great product. Quickly identify, prioritize, and resolve performance problems – memory bloat, N+1 queries, slow database queries, and more – with an agent that instruments the dependencies you need at a fraction of the overhead. Scout APM is built for developers, by developers, and monitors Ruby, PHP, Python, Node.js, and Elixir applications.

Capture all HTTP(S) traffic between your computer and the Internet with Telerik Fiddler HTTP(S) proxy. Inspect traffic, set breakpoints, and fiddle with requests & responses. Fiddler Everywhere is a web debugging proxy for macOS, Windows, and Linux. Capture, inspect, monitor all HTTP(S) traffic between your computer and the Internet, mock requests, and diagnose network issues. Fiddler Everywhere can be used for any browser, application, process. Debug traffic from macOS, Windows, or Linux systems and iOS or Android mobile devices. Ensure the proper cookies, headers, and cache directives are transferred between the client and server. Supports any framework, including .NET, Java, Ruby, etc. Mock or modify requests and responses on any website. It’s a quick and easy way to change the request and responses to test websites without changing code. Use Fiddler Everywhere to log all HTTP/S traffic between your computer and the Internet.

Bugsnag monitors application stability so you can make data-driven decisions on whether you should be building new features, or fixing bugs. ‍ We are a full stack stability monitoring solution with best-in-class functionality for mobile applications. Rich, end-to-end diagnostics to help you reproduce every error. A simple and thoughtful user experience for all your apps in one dashboard. The definitive metric for app health — the common language for product and engineering teams. Not all bugs are worth fixing. Focus on the ones that matter to your business. Extensible libraries with opinionated defaults and countless customization options. Subject matter experts who care deeply about error reduction and the health of your apps.

Remote logger, crash reporter and in-app user feedback Bugfender is a log storage service for application developers. Bugfender collects everything happening in the application, even if it doesn’t crash, in order to reproduce and resolve bugs more effectively and provide better customer support. Bugfender respects your user's privacy, is battery and network efficient and keeps logging even if the device is offline. Track and destroy bugs before users even notice. Bugfender logs all bugs on all devices and sends the results in seconds - enabling you to find and fix bugs before your users even get an error message. Achieve 5-Star Ratings. Bugfender doesn’t just log bugs and crashes. It logs all the information you’ll ever need so you can build a clear picture of your users and earn those crucial five-star ratings. Deliver world-class customer service. Our logging tool enables you to target individual users and provide personalized customer support.

Ambassador Edge Stack is a Kubernetes-native API Gateway that delivers the scalability, security, and simplicity for some of the world's largest Kubernetes installations. Edge Stack makes securing microservices easy with a comprehensive set of security functionality, including automatic TLS, authentication, rate limiting, WAF integration, and fine-grained access control. The API Gateway contains a modern Kubernetes ingress controller that supports a broad range of protocols including gRPC and gRPC-Web, supports TLS termination, and provides traffic management controls for resource availability. Why use Ambassador Edge Stack API Gateway? - Accelerate Scalability: Manage high traffic volumes and distribute incoming requests across multiple backend services, ensuring reliable application performance. - Enhanced Security: Protect your APIs from unauthorized access and malicious attacks with robust security features. - Improve Productivity & Developer Experience

Discover, predict, and resolve errors in real-time. Go beyond crash reporting, error tracking, logging and error monitoring. Get instant and accurate alerts — plus a real-time feed — of all errors, including unhandled exceptions. Our automation-grade grouping uses machine learning to reduce noise and gives you error signals you can trust.

Telepresence streamlines your local development process, enabling immediate feedback. You can launch your local environment on your laptop, equipped with your preferred tools, while Telepresence seamlessly connects them to the microservices and test databases they rely on. It simplifies and expedites collaborative development, debugging, and testing within Kubernetes environments by establishing a seamless connection between your local machine and shared remote Kubernetes clusters. Why Telepresence: Faster feedback loops: Spend less time building, containerizing, and deploying code. Get immediate feedback on code changes by running your service in the cloud from your local machine. Shift testing left: Create a remote-to-local debugging experience. Catch bugs pre-production without the configuration headache of remote debugging. Deliver better, faster user experience: Get new features and applications into the hands of users faster and more frequently.

See video, network and logs that led to bugs and crashes in live apps. No need to reproduce intermittent bugs. With Bugsee, all the crucial data is always there. All important traces from your app. Now you know what exactly led to unexpected behavior. See the video of all user actions, communication with the backend and system state that led to the problem. Get statistics on similar crashes. See trends broken down by device type, OS version and time. Get the exact filename, method and a line number of the crash. See states of all other threads running at the time of the crash. See all HTTP and HTTPS requests and responses – headers and body – from and to your app. Replay all app’s console logs synchronized to the video and network traffic.

Thundra is a developer platform company that empowers application teams to develop, debug, test, and monitor modern microservices on the cloud. By offering everything from automated instrumentation to cloud debugging and test optimization in a single platform, Thundra eliminates the need for multiple tools for pre-production and production environments

Log management. Upgraded. With Honeycomb. Honeycomb is built for modern dev teams to better understand application performance, debug & improve log management. With rapid query, find unknown unknowns across system logs, metrics & traces with interactive charts for the deepest view against raw, high cardinality data. Configure Service Level Objective (SLOs) on what users care about so you cut-down noisy alerts and prioritize the work. Reduce on-call toil, ship code faster and keep customers happy. Pinpoint the cause. Optimize your code. See your prod in hi-res. Our SLOs tell you when your customers are having a bad experience so that you can immediately debug why those issues are happening, all within the same interface. Use our Query Builder to easily slice and dice your data to visualize behavioral patterns for individual users and services (grouped by any dimensions).

Dev teams use Disbug chrome extension to capture bugs with screen recording, screenshots, console logs, network logs, user events and upload them to the project management tool, with a single click! Explain and narrate the problem visually. Let developers see exactly what happened when it went wrong. One-click capture of the entire context for bug reports. Instantly know what went wrong from every angle by capturing the complete session. Get consolidated technical logs directly in your favorite tools and with a link to see the detailed logs. Centralize everything in your issue trackers. Seamless integration with the tools of your choice. Automatically create tickets in the pre-configured issue tracker when you report the bug. Expedites the debugging process. Gives you more clarity and makes development easy. Cut down your bug reporting time by 60%. Streamline the work of QA testers, developers & project managers at costs less than a cup of coffee!

Reports arrive to you instantly, automatically supplemented with a ton of useful data so you can fix them 50X faster. Whenever users notice a bug, they just shake their phone to report it, without ever leaving your app. When they shake their device, Shake opens up and allows them to send you feedback without ever leaving your app. Report yourself any info from the user’s device you want. Use .setMetadata() to easily adjust the data to your debugging requirements. See the user’s taps around your app, .log() custom events and see all their network traffic prior to reporting the bug to you. On the web Dashboard you can, for example, effortlessly find only bugs reported from iPad Airs that were in landscape mode and offline. Get bug notifications immediately in your team chat. Or, have tasks created directly in your issue tracker of choice. Shake was built to play nicely with the tools your team already uses.

Defang is a developer-centric platform that simplifies the process of developing, deploying, and debugging cloud applications. By leveraging AI-assisted tooling, Defang enables developers to swiftly transition from an idea to a deployed application on their preferred cloud provider. The platform supports multiple programming languages, including Go, JavaScript, and Python, allowing developers to start with sample projects or generate project outlines using natural language prompts. With a single command, Defang builds and deploys applications, handling configurations for computing, storage, load balancing, networking, logging, and security. The Defang Command Line Interface (CLI) facilitates interactions with the platform, offering installation options via shell scripts, Homebrew, Winget, Nix, or direct download. Developers can define services using compose.yaml files, which Defang utilizes to deploy applications to the cloud.

Instabug provides in-app feedback and bug reporting to mobile apps. After integrating the SDK, it allows you to have seamless two-way communication with users or testers while providing detailed environment report for developers. The integration process takes less than a minute and the results are outstanding! The top apps in the world rely on Instabug. We provide exceptional support 24/7 and is constantly rated highly as a bug reporting & tracking tool. Expand your mobile team's understanding of performance and user experience to enable faster fix times, precise performance metrics and error prioritization. With visibility into 100% of user sessions, quickly prioritize to focus on the issues that matter most to you and your user’s experience. Quickly integrate instabug to your apps with a single line of code. Instabug enables your team to find the balance between new feature development and stability.

From error tracking to performance monitoring, developers can see what actually matters, solve quicker, and learn continuously about their applications - from the frontend to the backend. With Sentry’s performance monitoring you can trace performance issues to poor-performing api calls and slow database queries. Source code, error filters, stack locals — Sentry enhances application performance monitoring with stack traces. Quickly identify performance issues before they become downtime. View the entire end-to-end distributed trace to see the exact, poor-performing API call and surface any related errors. Breadcrumbs make application development a little easier by showing you the trails of events that lead to the error(s).

Using Seagence’s unique execution path technology combined with machine learning, receive realtime alerts with root cause when defects occur in your production Java applications. Fix your code without needing any debugging. Attach a lightweight runtime java agent when you start your application. As your users access the application, Seagence agent collects data about how requests are being processed. So give Seagence 24 hours to collect enough sample for analysis. The collected data is fed to Seagence's analytics engine in realtime which finds defects when they occur and alerts. Know that Seagence unearths all defects in your application including unknown. With Seagence provided defect and root cause in hand, you fix your broken code. Continuously monitoring your production application, Seagence proactively finds defects and their root cause in realtime thus eliminating the need for debugging.

Request Metrics makes web performance easy with real-user monitoring and automated Lighthouse testing—helping you boost Core Web Vitals, SEO, and user experience. Track real visitors, not just lab tests, with automatic noise cancellation, actionable insights, and detailed element attribution. Our scheduled Lighthouse tests detect regressions before they hurt rankings, while real-user data keeps you informed on how your site performs in the wild. Filter by page, device, region, or vendor to uncover performance bottlenecks, and get instant alerts when something slows down. With built-in vendor tracking, you’ll know exactly which third-party scripts are hurting your load times. No complicated setup, no code changes—just fast, reliable performance monitoring designed for modern websites. Get started for free today!