Example network recording
Load example to open a synthetic HAR with five requests.
5 requests, 1 HTTP error, and a 1.14 s recorded span. Select /api/projects?limit=10 to inspect its JSON response.
Frontend Tools
HAR Viewer
Open a HAR file to explore network requests, waterfalls, headers, and response bodies. Private, readable, and entirely in your browser.
Processed locally · Your input stays in your browser
Every request, in context.
Open a HAR file or explore the example recording.
Network recording
Your network, at a glance
Open a HAR file to explore slow requests, errors, and response payloads.
bytebench / har-viewerLocal
Overview details
Ready when you are.
Select a request to inspect its details
How to use this tool
Choose or drop a HAR file exported from your browser’s Network panel. Search requests, filter HTTP errors, and sort by duration or body size. Select a request to inspect its headers, query parameters, payload, response, and timing details in the terminal panel.
- Choose or drop a HAR file exported from your browser’s Network panel.
- Search, filter, or sort requests, then select one to inspect.
- Review validation messages before copying the output.
- Use the example button when you want a known-good starting point.
Examples
Common use cases
- Find slow API requests and HTTP errors in a browser recording.
- Inspect request headers, cookies, query parameters, and response payloads.
- Understand request overlap using a shared waterfall timeline.
When to use this tool
Use this HAR viewer page when you need to inspect HTTP Archive network recordings quickly during debugging, review, migration, or documentation work and want to keep raw input in your browser session.
If your task shifts, JSON Formatter and URL Parser are usually the next useful tools.
Input and output expectations
- Expected input shape: An uncompressed HAR JSON file containing log.entries, up to 20 MB and 10,000 requests.
- Typical output: A searchable request waterfall with read-only headers, payloads, responses, and timing details.
- Quick input example: Load example to open a synthetic HAR with five requests.
- Quick output example: 5 requests, 1 HTTP error, and a 1.14 s recorded span. Select /api/projects?limit=10 to inspect its JSON response.
Common mistakes to avoid
- Expecting a body that was not captured in the export.
- Treating unknown sizes or timings as zero.
- Adding TLS time twice when it is already included in connect time.
Notes and edge cases
Response body bytes exclude headers; unknown sizes are reported separately. The recorded span measures the earliest request start to the latest recorded end, not page load time. TLS time is already included in connect time. HTML and scripts are shown as inert text. The viewer inspects recorded data and does not validate server trust or replay requests.
For privacy-sensitive data, keep using the tool in a trusted browser session and avoid pasting secrets into shared screens, screenshots, browser extensions, or remote support sessions.
FAQ
Is my HAR file uploaded?
No. File contents are read in your browser tab and are not uploaded or saved in browser storage. Recorded URLs are displayed as text and are never replayed. Clear the tool or close the tab when finished.
How do I create a HAR file?
Open your browser developer tools, select Network, record the activity you want to investigate, then use the export HAR option. HAR files may contain authentication headers, cookies, and personal data, so handle exports with care.
Why is a response body or timing missing?
HAR exports vary. Bodies may be omitted or sanitized, and unavailable timing and size measurements appear as Unknown. UTF-8 Base64 text responses are decoded locally; binary bodies are not rendered.
What are the limits?
Open one uncompressed HAR or JSON file up to 20 MB with at most 10,000 requests. Requests are paginated in groups of 50; text previews are limited to 100,000 characters. Larger encoded bodies are omitted with an explanation.