Debugging production errors often feels like searching for a needle in a haystack without the right tools. Sentry transforms this process by capturing errors in real-time, providing context like stack traces and user info, so you can fix issues faster and improve application stability.
Verdict
Sentry’s free “Developer” plan offers a powerful entry point for solo developers and small projects, providing 5,000 errors and 5 million performance spans per month at no cost. It’s an excellent choice for monitoring a new application or side project without upfront expense.
How This Guide Was Built
This guide is based on direct verification of Sentry’s official resources. We followed the official getting-started documentation, analyzed the pricing details on Sentry’s official pricing page, and confirmed the signup flow and initial project setup. The free tier limits, setup steps, and code examples are drawn directly from these sources. We did not test paid Team or Business plan features, such as third-party integrations or SAML/SCIM provisioning, which are described based on official documentation. All information was verified against official sources in August 2026.
What is Sentry?
Sentry is a developer-first application monitoring platform that helps you find and fix crashes in real-time. Its core capabilities are error monitoring and performance tracing. It captures exceptions across your entire stack, groups them for clarity, and provides rich diagnostic data like breadcrumbs, user context, and release information. Beyond errors, Sentry tracks performance metrics, allowing you to trace requests across services and identify slow operations, helping you build more reliable applications.
How do I get started with Sentry?
You can get started with Sentry by signing up for a free account, creating a project, and installing the appropriate SDK in your application. The process takes under ten minutes and requires no credit card. According to Sentry’s official getting-started docs, the flow is straightforward and designed for quick integration.
Step 1: Sign Up and Create a Project
- Go to sentry.io and create a free account.
- After verifying your email, you’ll be prompted to create your first organization.
- Next, select “Create a project.” Choose the platform you’re using (e.g., JavaScript, Python, React, Node.js).
- Give your project a name and confirm. Sentry will generate a DSN (Data Source Name), which is a unique URL your app will use to send events. Copy this DSN and keep it safe.
Step 2: Install the SDK and Initialize
Install the Sentry SDK for your framework. For a basic JavaScript/React web app, use npm:
npm install @sentry/react
# or for vanilla JS:
npm install @sentry/browserThen, initialize Sentry as early as possible in your application’s entry point (e.g., index.js or App.js). Paste the DSN you copied earlier.
import * as Sentry from "@sentry/react";
Sentry.init({
dsn: "YOUR_DSN_HERE",
// We recommend adjusting this value in production:
tracesSampleRate: 1.0,
// Session Replay captures a video-like replay of a user's session
replaysSessionSampleRate: 0.1,
replaysOnErrorSampleRate: 1.0,
});The tracesSampleRate controls what percentage of transactions are captured for performance monitoring. The replaysSampleRate options control session replay capture.
Step 3: Trigger a Test Error
To verify your setup works, throw a test error in your app. For example, add a button that triggers an error:
<button onClick={() => { throw new Error("Test error from Sentry!"); }}>
Break the world
</button>Click the button, then go to your Sentry dashboard. Within moments, you should see the error appear in your project’s “Issues” stream, complete with stack trace, browser info, and other context.
Sentry Free Tier Limits
Sentry’s free “Developer” plan provides a robust set of features for individual developers with no time limit. The plan is limited to one user but includes generous monthly quotas for core monitoring capabilities. The following table details the inclusions as of August 2026, verified on Sentry’s official pricing page.
| Feature | Free Tier Allocation (Monthly) |
|---|---|
| Errors | 5,000 |
| Performance Spans (Tracing) | 5,000,000 (5M) |
| Logs | 5 GB |
| Application Metrics | 5 GB |
| Session Replay | 50 replays (Note: New users get 5,000 replays/month for the first 3 months) |
| Uptime Monitors | 1 |
| Cron Monitors | 1 |
| Metric Monitors | 20 |
| Attachments | 1 GB |
| Size Analysis Builds | 100 |
| Custom Dashboards | 10 |
| Projects | Unlimited |
| Data Retention | 30-day lookback |
| Alerts | Email only (Slack, Discord, etc. require Team plan) |
| Users | 1 (solo developer) |
When you outgrow the free tier, paid plans start at $26/month for Team (unlimited users and third-party integrations) and $80/month for Business (SAML/SCIM and unlimited dashboards), per Sentry’s official pricing page.
Common Mistakes Beginners Make
1. Forgetting to Set a Sample Rate
By default, Sentry might not capture any performance data. You must set tracesSampleRate in your Sentry.init() options to a value between 0.0 and 1.0 (e.g., 0.2 for 20% of transactions) to enable tracing. Without this, you’ll only get error monitoring.
2. Not Using Source Maps If your code is minified or bundled, stack traces will be unreadable. After building your app, upload your source maps to Sentry using their CLI or build plugins. This allows Sentry to map minified code back to your original source, making debugging significantly easier.
3. Leaving replaysSessionSampleRate at 0
Session Replay gives you a visual replay of a user’s session leading up to an error. Beginners often miss this feature by not configuring the replay sample rates in Sentry.init(). Enable it to gain crucial visual context for understanding how an error occurred.
4. Ignoring Alert Rules The default email alerts can be noisy. Before deploying to real users, create a custom alert rule in Sentry to notify you only for new issues or critical errors. This prevents alert fatigue and ensures you see the most important problems first.
Troubleshooting Common Sentry Setup Issues
Even with a straightforward setup flow, beginners run into a few recurring problems worth knowing about before they happen.
1. No errors appear in the Issues stream. If you trigger a test error but nothing shows up, check that your DSN is correct and that the SDK is initialized before any other code runs. A common cause is initializing Sentry inside a component that renders later, which can miss early errors. Also verify that the project in your dashboard matches the DSN you copied — pasting a DSN from a different project sends events to the wrong place.
2. Performance data is missing. As noted above, tracing requires an explicit tracesSampleRate. If you set it but still see no transactions, confirm that your framework’s router or fetch instrumentation is installed. For React apps, @sentry/react includes tracing instrumentation, but you need to import the tracing integrations as shown in the official docs.
3. Source maps aren’t resolving. Stack traces that show minified names like e.exports mean source maps weren’t uploaded. After building, run Sentry’s source map upload command or use the framework plugin. Verify the upload by checking the “Source Maps” section of your project settings — the number of uploaded maps should match your build output.
4. Quota runs out faster than expected. Session Replay and attachments consume quota quickly. If you hit the 5,000 error limit or 5 GB log limit early, reduce replaysSessionSampleRate and attach smaller files, or sample errors to only capture a percentage of events. Monitoring your usage on the dashboard helps you calibrate before the limit resets.
FAQ
Is Sentry free for beginners?
Yes, Sentry offers a permanently free “Developer” plan that is ideal for beginners and individual developers. The plan requires no credit card, includes 5,000 errors and 5 million performance spans per month, and provides all core error monitoring and tracing features. It is limited to one user, making it perfect for personal projects or learning. For full details, see Sentry’s official pricing page.
How many errors can I track on Sentry’s free tier?
On the free “Developer” plan, you can track up to 5,000 errors per month. This quota resets at the beginning of each calendar month. This limit applies to the number of error events Sentry ingests and processes; you can have unlimited projects that feed into this pool. Once the limit is reached, no new errors will be captured until the next month.
Does the free plan include performance monitoring?
Yes, the free plan includes performance monitoring, known as Tracing. You are allocated 5,000,000 (5M) spans per month. A span represents a single unit of work within a trace, such as a database query or an API call. This allows you to monitor application performance and identify slow transactions alongside error tracking, as detailed on Sentry’s official pricing page.
Where to Go Next
You’ve successfully instrumented Sentry and can now see errors from your application. Explore more advanced features like setting up performance tracing with custom transactions, configuring alert rules to notify your team, or integrating with issue trackers like Jira. Check out our Grafana Cloud free tier guide for complementary visualization, or see our Upstash free tier guide for a serverless data stack. For a quick reference to all of Sentry’s free tier benefits, visit Sentry’s directory entry.
References
[1] Sentry’s official pricing page [2] Sentry’s official getting-started docs [3] sentry.io