HAR File Viewer Online
Inspect HAR archives in seconds with a privacy-first workflow. Upload a file, pinpoint bottlenecks, export filtered requests to CSV, and copy a performance snapshot your team can act on.
Selected request details
Choose a row to see headers, timings, and payload metadata.
About This HAR Viewer
HAR File Viewer Online is a performance analyst’s companion, engineered to open even weighty HTTP Archive exports without sending a single byte to a server. After surveying popular developer forums and performance communities, we noticed that most HAR viewers feel dated, lack deep filtering, or make it difficult to share takeaways. This tool fixes those gaps with a premium interface, subtle guidance, and productivity perks that make triaging regressions faster than ever.
From the first paint, the experience is tuned for speed: lightweight vanilla JavaScript, pre-sized layout containers that prevent layout shift, and a responsive grid that flexes beautifully from mobile to desktop. Every upload is processed locally, so debugging remains confidential whether you are auditing a SaaS product, comparing CDNs, or documenting a regression for a sprint retro. The built-in Performance Snapshot groups top slow endpoints, dominant mime types, and cumulative payloads — data you can copy in one click to share with engineers or stakeholders.
How to Use the HAR Analyzer
Working with your archive is simple. Import a HAR file via drag-and-drop or the file picker and the viewer instantly parses entries, normalizes timings, and populates the table. Use the live search, method filter, and content type filter to narrow the dataset. Click any row to inspect request and response headers, payload metrics, and timing breakdowns.
- Select or drop a HAR file. No upload limits, and processing happens offline.
- Scan the Summary bar to spot total requests, transfer size, critical path, and key domains.
- Filter or sort columns to isolate slow, large, or error-prone requests.
- Export the filtered results to CSV or copy the Performance Snapshot to brief your team.
Pro Tips
- Combine the search box with the content-type filter to quickly surface uncompressed assets.
- Sort by Total Time to expose slow third-party services before they affect your LCP.
- Load the sample dataset to demonstrate findings in training sessions without sharing client data.
- Use the copied snapshot inside tickets or runbooks so every fix request includes data-backed context.
FAQs
Is my HAR data uploaded anywhere?
Never. Parsing, filtering, exporting, and copying all happen entirely inside your browser session.
Can I export only selected rows?
Yes. Apply search or filters first, then use Export CSV to download precisely what you are viewing.
Does the tool handle massive HAR files?
The viewer is optimized for efficiency. For very large archives, use filters early to keep the interface smooth.
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