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Yes. Core tools are free. Heavy work runs in your browser so your payloads are not processed on Spoold servers for formatting, decoding, and similar utilities.

Is my data safe with Spoold?

Tool processing for supported client-side utilities happens in your browser. Encrypted share links are designed so only people with the link can read the payload. Review the Privacy Policy for details on local storage, analytics, support, and third-party services.

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HAR Viewer Online — Inspect Chrome DevTools Network Logs

Inspect HAR 1.2 network captures: filter by status, search URLs, and read headers and bodies. Parsed locally in your browser.

Guide: HAR Viewer

↑ Back to tool

What is this tool?

This HAR viewer online opens HTTP Archive (HAR 1.2) files and lists every request with method, status, URL, time, and size. Filter by 2xx / 3xx / 4xx / 5xx, search by URL, and click any row to inspect request and response headers, query strings, cookies, bodies, and a timing breakdown. Everything runs in your browser.

Drop a .har file or paste the JSON to get a clear picture of what the browser actually did: failed calls, slow endpoints, redirects, and unexpected payloads.

💡 Quick tip

Start with the 4xx and 5xx chips to find failures, then search for an API path to jump to the exact request.

Why use a HAR viewer?

Debug a customer's bug report from a HAR they attached, without asking for screenshots
Check CORS, cache, and auth headers on real responses
Find slow or oversized requests when investigating performance
Read HAR files without opening DevTools or installing extensions

Key features

Drop or paste — .har files or raw JSON.
Status chips with counts — All, 2xx, 3xx, 4xx, 5xx.
URL search — Instant substring filter.
Entry inspector — Headers, request, response, and timing tabs.
Safe previews — Large bodies are truncated; base64 text is decoded; JSON is pretty-printed.
History — Recent HAR summaries (no headers or bodies).

How to use

Load a HAR — Drop the file on the upload area, choose it, or use Paste JSON.
Filter — Click a status chip or type part of a URL.
Select a row — Review headers, bodies, and timings in the inspector below the table.
Copy the URL — Use it in the HTTP Request tool to reproduce the call.

How to export a HAR file

Chrome / Edge — DevTools → Network → enable Preserve log → reproduce → right-click → Save all as HAR with content.
Firefox — DevTools → Network → gear or right-click → Save All As HAR.
Safari — Web Inspector → Network → Export.

Use cases

Scenario	How this tool helps
Support escalations	Open a customer's HAR and jump straight to the failing 4xx/5xx call.
Performance	Spot slow requests and large responses by time and size columns.
API & CORS debugging	Inspect real request and response headers, including preflights.

Privacy

HAR files often contain session cookies, Authorization headers, API keys, and personal data. This viewer never uploads them, but you should still sanitize a HAR before sharing it with anyone, and avoid opening sensitive captures on shared machines.

Common mistakes

Exporting without content — "Save as HAR" without content leaves response bodies empty.
Log not preserved — Navigation clears the Network panel unless Preserve log is on.
Treating time as server time — Entry time includes DNS, TLS, queueing, and download, not just backend processing.

FAQ

What is a HAR file?

HTTP Archive (HAR) is a JSON format that records a browser's network activity: every request and response with headers, timings, and optionally bodies. The current version is HAR 1.2.

Is my HAR uploaded anywhere?

No. The file is read and parsed in your browser. History keeps only a compact list of requests (method, status, URL, time, size) — never headers, cookies, or bodies.

Why are some bodies missing?

Browsers often omit response bodies (especially images, scripts, or when 'Preserve log' content is off). If the HAR has no content.text for an entry, there is nothing to show.

Why is a body truncated?

To keep the page responsive, previews show the first 20,000 characters. The total length is displayed so you know how much was cut.

How big a file can I open?

Files up to 100 MB are accepted, but very large captures are limited by browser memory. The table renders the first 500 matching rows; use the filters to narrow down.

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Conclusion

This HAR viewer turns a dense JSON capture into a readable request list with the filters you need. Look up unfamiliar codes in the HTTP Status Codes reference, or pretty-print a body with the JSON Formatter.