Best Free Debugging Tools in 2026

Session replay & error tracking

4.7/5 across G2 and Capterra · 2,463 ratings, Sep 2026

LogRocket is a session replay and product analytics platform with pixel-perfect recordings, JavaScript error reporting, and AI-powered struggle detection for understanding user behavior.

Terminal UI to manage Kubernetes clusters

4.2/5 across G2 and Trustpilot · 4,926 ratings, Aug 2026

K9s manages Kubernetes clusters from the terminal. Navigate resources, tail logs, exec into pods-kubectl power with a terminal UI. The navigation is fast. Common operations are keyboard-accessible. The overview is comprehensive. Kubernetes operators use K9s because terminal navigation is faster than dashboard clicking.

Real-time error tracking and debugging

4.5/5 across G2 and Capterra · 435 ratings, Sep 2026

Rollbar monitors errors across stack and platforms. Error tracking with real-time alerting-catch problems before users report them. The grouping is intelligent. The real-time helps. The platform coverage is broad. Development teams monitoring production use Rollbar for comprehensive error tracking.

Application monitoring & error tracking

4.6/5 across G2 and Capterra · 297 ratings, Sep 2026

Sentry is an application monitoring platform providing error tracking, performance tracing, session replay, and uptime monitoring with event-based pricing for development teams of all sizes.

Debug production issues instantly without pausing threads

4.5/5 on G2 · 222 ratings, Sep 2026

Hyperprobe is an AI-powered production debugger that eliminates the log-and-redeploy cycle. It places read-only virtual breakpoints (probes) directly into running services to capture exact variable state at the moment of failure, without pausing threads or modifying code. The tool integrates with alerting systems like PagerDuty, Datadog, and Slack, automatically scouting traces to locate the root cause and deploying probes on the suspect line. It works with coding agents such as Cursor, Claude Code, Codex, and Opencode via an MCP server, enabling engineers to diagnose incidents in minutes instead of hours. Hyperprobe supports JavaScript, TypeScript, Java, Python, and Ruby, and offers managed cloud or self-hosted deployment with built-in PII redaction and immutable audit logs.

Accelerate product decisions with comprehensive analytics, session replays, and developer tools.

4.6/5 across G2 and Capterra · 138 ratings, Sep 2026

LiveSession is a product analytics platform designed to help product teams, designers, developers, UX researchers, and marketers understand user behavior and make data-driven decisions. It combines qualitative insights from high-quality session replays with quantitative data from custom metrics, funnels, and dashboards. The platform allows users to track key performance indicators, analyze user journeys, identify pain points, and debug issues efficiently. With features like heatmaps, clickmaps, console logs, and network requests, LiveSession provides a holistic view of user interactions and application performance. It emphasizes a privacy-first approach, offering automatic anonymization of sensitive data and compliance with GDPR and CCPA standards. LiveSession aims to foster continuous product discovery and empower all team members to act on product data, ultimately leading to better products, improved user experience, and increased conversions across various industries.

See your code in action, across any environment, with AI-powered runtime debugging.

4.8/5 on G2 · 67 ratings, Mar 2026

Lightrun is a developer observability platform that provides real-time, line-level code context across the entire Software Development Life Cycle (SDLC). It supercharges IDEs and AI Agents by allowing developers to debug and remediate software issues autonomously, powered by live runtime data. The platform enables engineers to add dynamic logs, metrics, and snapshots to live applications without stopping, redeploying, or modifying code. Lightrun is designed for engineering teams that need to quickly pinpoint and resolve issues in complex, distributed environments, including production. It helps reduce Mean Time To Resolution (MTTR) by providing immediate visibility into application behavior, even for elusive bugs that only appear in specific environments. The tool integrates directly into popular IDEs like IntelliJ and Visual Studio Code, offering a seamless debugging experience for cloud-native, on-premise, containerized, and serverless applications.

AI-powered session replays, error tracking, and analytics for optimizing user experience.

4.9/5 on G2 · 52 ratings, Sep 2026

Zipy is an AI-driven platform designed to help engineering, product, and marketing teams understand user behavior, detect errors, and optimize conversions. It provides AI-powered session replays that automatically identify and prioritize UI bugs and user frustration points, eliminating the need to manually sift through countless recordings. The platform translates technical errors into user-facing messages, making issues understandable for both technical and non-technical teams. Beyond session replays, Zipy offers robust error tracking capabilities, capturing frontend JavaScript errors and API failures across various frameworks like React, Angular, and Vue.js. It provides real-time monitoring, smart alerts, and detailed context for debugging, allowing teams to quickly identify, prioritize, and resolve issues. By unifying user session replay, frontend, and network monitoring, Zipy aims to accelerate growth by proactively addressing user experience problems and improving debugging efficiency.

Self-hostable session replay and product analytics for understanding user behavior and troubleshooting issues.

4.9/5 on SourceForge · 47 ratings, May 2026

OpenReplay offers a comprehensive platform for digital experience analytics, combining session replay with product analytics. It allows users to see exactly how customers interact with their applications, identifying friction points, understanding user behavior, and troubleshooting issues faster. The platform captures every click, scroll, and interaction, along with technical details like console logs, network activity, and state changes, enabling teams to debug and resolve problems efficiently. Beyond debugging, OpenReplay provides product analytics features such as funnels, user journeys, trends, and heatmaps to help product teams understand user engagement, measure the impact of changes, and prioritize development. A key differentiator is its self-hosting capability, which gives organizations complete control over their customer data, ensuring privacy and compliance with strict regulatory standards. It's designed for engineering, product, customer support, and design teams looking to improve their digital products.

Observability for distributed systems

4.7/5 across G2 and Capterra · 55 ratings, Sep 2026

Honeycomb is an observability platform for distributed systems that helps teams debug production issues using high-cardinality data and distributed tracing.

An online code playground for quickly testing and sharing HTML, CSS, and JavaScript snippets.

4.3/5 on SourceForge · 67 ratings, May 2026

JSFiddle is a popular online code editor that allows developers to write, test, and share front-end code snippets directly in their web browser. It supports HTML, CSS, and JavaScript, along with various pre-processors like HAML, SCSS, SASS, and PostCSS, and a wide array of JavaScript frameworks and libraries such as jQuery, React, Vue, Angular, D3, and many more. This makes it an invaluable tool for rapid prototyping, debugging, and demonstrating web development concepts without the need for a local development environment. The platform offers features like live code validation, auto-save, hot reloading for CSS and HTML, and code autocompletion with contextual awareness. Recent updates include a switch to the Monaco editor (used in VSCode) for an enhanced editing experience, AI code completion (beta) powered by the Codestral model, and a CSS Flexbox generator. JSFiddle is ideal for front-end developers, educators, and anyone looking to quickly experiment with web technologies or share runnable code examples.

The AI gateway with built-in observability for LLM applications.

4.3/5 on SourceForge · 67 ratings, Mar 2026

Keywords AI is an LLM monitoring platform designed for AI startups and developers. It provides a unified developer platform for building, testing, monitoring, analyzing, and optimizing large language model (LLM) applications. The platform allows users to route, trace, evaluate, and debug every LLM request with minimal code changes, offering a single interface for various LLMs and bypassing rate limits for scalable operations. This tool is ideal for developers and teams working on LLM-powered products, from initial MVP to full production. It streamlines the LLM development lifecycle by offering features like a unified API endpoint, prompt management with A/B testing, pre-built dashboards for monitoring LLM metrics, and tools for collecting datasets to fine-tune models. Keywords AI aims to simplify the complexities of LLM infrastructure and observability, enabling faster development and better performance optimization.

Error monitoring with diagnostic data for debugging

4.4/5 across SourceForge, G2 and Capterra · 55 ratings, Sep 2026

Bugsnag captures errors from your applications with the context needed to fix them. Not just stack traces-user steps, device info, deployment details, and whatever custom data helps understand what went wrong. Stability metrics show overall application health. Alerts prevent drowning in notifications. Integrations create issues in your project tracker. Development teams who need error monitoring that surfaces actionable information use Bugsnag to find and fix bugs before users complain.

Real-time log aggregation and analysis for DevOps

4.4/5 on G2 · 51 ratings, Sep 2026

Papertrail aggregates logs from servers, apps, and cloud services for troubleshooting and monitoring. DevOps teams search and analyze logs in real-time with instant alerts on patterns. The platform simplifies log management with minimal setup required.

Open-source Kubernetes observability for developers with auto-instrumentation and scriptable debugging.

4.9/5 across G2 and SourceForge · 30 ratings, Mar 2026

Pixie is an open-source Kubernetes monitoring and application debug platform designed for developers. It provides deep visibility into Kubernetes clusters by automatically collecting metrics, events, traces, and logs without requiring any code changes, leveraging dynamic eBPF probes. This allows developers to debug applications and infrastructure directly within their Kubernetes environment. The platform offers a CLI for health checks and charts, enabling developers to stay within their workflow, and a 'Live' interface for navigating data. A key feature is its scriptability, allowing users to run and share custom or community-contributed PXL scripts for debugging. Pixie is Kubernetes-native, meaning it runs entirely within the cluster and does not store customer data externally, addressing concerns about data egress and cost associated with off-cluster telemetry. It supports various Kubernetes distributions like Minikube, EKS, GKE, AKS, and self-managed clusters.