500
Server errors
The backend failed. The response body often holds the error message.
Free tools
HAR file analyzer & sanitizer
A HAR file holds the session cookies and tokens of whoever recorded it. Find the request that failed, then strip the secrets before you pass the file on. It never leaves your browser.
The file is read in your browser. Nothing is uploaded, and there’s no share link.
HAR analyzer & sanitizer · read in this browser tab only
What we found
No failed, slow or heavy requests in this file.
Status
Method
URL
Type
Size
Time
Waterfall
Timing
No requests match these filters.
Remove secrets before you share
A HAR file carries session cookies and tokens, and anyone holding it can use them until they expire. Stolen support HAR files were behind the Okta breach in 2023.
Everything ticked is replaced with [redacted] in the copy you download. Untick what you want to keep.
Name
Found in
Values
Starts with
No cookies, tokens or passwords found.
The check looks for common names like token, password or session, and for JWTs. It can’t spot every secret, so skim the copy before you send it.
Your file stays in this browser tab. Ybug never sees it, and closing the tab clears it.
How to save a HAR file
Record the problem with your browser’s developer tools, then export the Network tab. It takes about a minute.
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1
Open the page where the problem happens.
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2
Press F12 (⌘ Cmd+⌥ Option+I on a Mac) and open the Network tab.
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3
Tick Preserve log, reload the page and repeat what went wrong.
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4
Click the Export HAR icon (the down arrow) in the Network toolbar and save the file.
Chrome 130 and newer leave cookies and authorization headers out of this export by default.
-
1
Open the page where the problem happens.
-
2
Press F12 (⌘ Cmd+⌥ Option+I on a Mac) and open the Network tab.
-
3
Tick Persist Logs in the gear menu, reload the page and repeat what went wrong.
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4
Right-click any request and choose Save All As HAR.
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1
Turn on the developer tools: Safari → Settings → Advanced → Show features for web developers.
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2
Open the page, press ⌘ Cmd+⌥ Option+I and open the Network tab.
-
3
Tick Preserve Log, reload the page and repeat what went wrong.
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4
Click Export in the Network tab and save the file.
A HAR file holds everything the page sent, cookies and tokens included. Sanitize it above before you email it or attach it to a ticket.
What to look for in a HAR file
Most “it doesn’t load” bugs show up as one of these.
401 / 403
Expired session or missing access
The request went out without a valid token or cookie.
(failed)
Requests that never got an answer
CORS, ad blockers, DNS and TLS problems end before any status code.
Waiting 4.2 s
Slow server responses
A long Waiting (TTFB) time means the server took its time, not the network.
3.4 MB
Heavy payloads
Oversized images, scripts and JSON responses slow down every page view.
301 → 302 → 200
Redirect chains
Every hop adds a round trip, and a loop never finishes loading.
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Frequently asked questions
What is a HAR file?
A HAR (HTTP Archive) file is a JSON log of every request the browser made while the Network tab was recording: URLs, headers, cookies, timings and often the response bodies. Support teams ask for one when a page fails in a way they can’t reproduce.
Is my HAR file uploaded anywhere?
No. This page reads the file with JavaScript in your browser. Nothing is sent to Ybug or anyone else. There’s no share link either, because a HAR file is too sensitive to keep on a server. Close the tab and it’s gone.
Is it safe to share a HAR file?
Only after you’ve cleaned it. A raw HAR file holds session cookies, authorization headers and tokens, and anyone holding the file can use them until they expire. Use Sanitize & download to replace them with [redacted], then skim the copy before you send it.
What does the sanitizer remove?
Cookies, Authorization headers and other token or API key headers, query and form parameters named like token, password, secret or code, matching JSON fields in request and response bodies, and anything shaped like a JWT. You review the list and untick what you want to keep. It goes by names and patterns, so a secret stored under an unusual name can slip through.
How do I turn a HAR request into a cURL command?
Open the request and click Copy as cURL. You get a command with the same URL, method, headers and body, ready to paste into a terminal. It includes cookies and tokens, so don’t paste it anywhere public.
Why is the response body missing?
Not every export includes response bodies. Browsers skip some, for example when the request was cancelled or served from cache, and some tools strip them on purpose. The status, headers and timing are still there.
Can Ybug record network requests automatically?
Yes. On STARTUP and higher plans, the Ybug feedback widget records XHR and fetch requests with every bug report, so nobody has to open DevTools or export a file. The browser extension doesn’t record them.
Tired of asking clients for HAR files?
Ybug’s feedback widget records network requests with every bug report, on STARTUP and higher plans. See what it captures.
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