Error tracking and performance monitoring platform for detecting, triaging, and resolving issues in web and mobile applications.
Pricing: 26 USD · Updated 2026-09-03
productivityYes. Sentry offers a Developer free tier with limited events; the paid Team plan starts at $28/month (price checked 2026-09-03).
Sentry is an error tracking and performance monitoring platform for detecting, triaging and resolving issues in web and mobile applications.
What an API is, how REST APIs work over HTTP, the methods you'll actually meet — GET, POST, PUT, PATCH, DELETE — and how to read a response.
Learn to create a production-ready RESTful API using Node.js and Express: setup, routing, middleware, environment variables, error handling, and deployment best practices — with a practical CRUD example for managing resources.
Cross-Origin Resource Sharing (CORS) is the mechanism browsers use to allow or block requests between different origins. This guide explains how CORS works, why it exists, common errors, and how to fix them.
Cross-Site Scripting (XSS) lets an attacker run their own JavaScript in another user's browser. This guide explains how the three types work and the defenses that stop them.
Cross-Site Request Forgery (CSRF) tricks a logged-in browser into sending unwanted requests to a trusted site. This guide explains how the attack works and the defenses that stop it.
Server-Side Request Forgery (SSRF) lets an attacker abuse a server's own URL-fetching feature to reach internal systems and cloud metadata. This guide explains the attack and the defenses that stop it.
Node.js errors come in several asynchronous styles, and each has its own correct way to be caught. This guide explains try/catch for synchronous code, error-first callbacks, promise rejection handling, and the 'error' event for streams and event emitters.
A Content Security Policy (CSP) is an HTTP security header that tells a browser which resources a page is allowed to load. Learn how CSP works, what directives are available, and how to deploy it without breaking your site.
Core Web Vitals are a set of Google metrics that measure the real-user experience of a web page: loading, interactivity, and visual stability. Learn what LCP, INP, and CLS measure, their target thresholds, and how to improve them.
Observability is the ability to infer a system's internal state from its external outputs. Learn how the three pillars — logs, metrics, and traces — work together, the difference between monitoring and observability, and the four golden signals (latency, traffic, errors, saturation).
Lazy loading is a performance strategy that defers non-critical resources (images, iframes, JavaScript, CSS) until they are needed. Learn what can be lazy-loaded, the native loading attribute, the Intersection Observer API, and when lazy loading helps or hurts.
