How to Use the HAR File Viewer:
Upload a HAR file (exported from browser DevTools) or paste HAR JSON data into the input field. Click Analyze to view all network requests, response times, and performance metrics. Filter requests by type, status code, or domain to focus on specific issues. Perfect for debugging slow WordPress page loads and API performance.
WordPress Performance
Analyze HAR files to identify slow-loading resources, blocking requests, and performance bottlenecks in WordPress sites.
API Debugging
Inspect REST API requests and responses to debug endpoint performance, error responses, and network issues.
Network Analysis
Review all network requests made by a page to understand resource loading patterns and optimization opportunities.
How Do HAR Files Work?
HAR (HTTP Archive) files are JSON-formatted logs of all network requests made by a browser. They contain request/response headers, timing data, and content information, providing a complete picture of network activity.
Request Logging
HAR files record every HTTP request made during page load, including URLs, methods, headers, and response data.
Timing Data
Contains detailed timing information for each request: DNS lookup, connection, SSL, request, response, and total time.
Performance Metrics
Provides insights into page load performance, resource blocking, and optimization opportunities based on request patterns.
Exporting HAR Files:
// In Chrome DevTools:
// 1. Open Network tab
// 2. Load your page
// 3. Right-click in Network tab
// 4. Select "Save all as HAR with content"HAR file saved How to export HAR file from browser DevTools
Frequently asked questions
Open browser DevTools (F12), go to Network tab, load your page, then right-click and select “Save all as HAR with content”.
HAR files contain all network requests, request/response headers, timing data, response content, and performance metrics.
Yes, HAR files capture all network requests including WordPress REST API calls, making it easy to debug API performance issues.
Collect Better Feedback with Userback
This HAR file viewer helps you analyze network performance efficiently, but gathering feedback about performance issues and network problems requires comprehensive context. Userback captures detailed visual feedback when users report slow page loads, network errors, or performance bottlenecks. With automatic screenshot capture, browser information, console logs, and network activity, you get complete visibility into performance-related issues. When developers need to report HAR analysis findings or suggest improvements to performance workflows, Userback enables them to submit detailed feedback that includes performance metrics and all technical context in a single shareable report.