What is a HAR file analyzer?

A HAR analyzer opens an HTTP Archive (.har) export and lists each network request—method, URL, status, timing, and size—so you can debug failed calls and slow loads without reopening DevTools.

How do I open a HAR file online?

Drop a .har (or paste the JSON) into this viewer. Entries appear in a searchable table. Click a row for headers, query string, timings, and a response preview. Everything stays in your browser.

Is this a HAR file viewer and analyzer?

Yes. You can view the full entry list and analyze it with search, status filters (2xx/4xx/5xx), method filters, and per-request timing breakdowns.

Is my HAR file uploaded?

No. Parsing runs locally with FileReader / JSON.parse. HAR exports often contain cookies and tokens—local-first viewing keeps them on your device.

How do I get a HAR file in Chrome?

Open DevTools → Network, enable Preserve log, reproduce the issue, then use Export HAR (download icon). Upload that file here to analyze it.

What should I look for when analyzing a HAR?

Start with 4xx/5xx and status 0 (blocked/failed), then sort attention to high timeMs rows and large response sizes. Inspect response bodies and headers for error messages.

sample.harUwarp Sample3 requests2 failed186 ms total time1.3 KB

#	Method	Status	Time	Size	URL
1	GET	200	128 ms	1.2 KB	https://example.com/
2	GET	500	45 ms	54 B	https://example.com/api/user
3	POST	401	12 ms	31 B	https://example.com/api/login

GET 200 OK

https://example.com/

text/html · 128 ms · 1.2 KB

Timings

blocked: 1 msdns: 12 msconnect: 20 mssend: 1 mswait: 80 msreceive: 14 ms

Request headers

Accept: text/html

Response headers

Content-Type: text/html; charset=utf-8

Response preview

<!doctype html><title>Example</title>

Drop HAR file

.har / .json — max 40 MB

Status

Method

Or paste HAR JSON

{
  "log": {
    "version": "1.2",
    "creator": { "name": "Uwarp Sample", "version": "1.0" },
    "entries": [
      {
        "startedDateTime": "2026-09-22T12:00:00.000Z",
        "time": 128.4,
        "request": {
          "method": "GET",
          "url": "https://example.com/",
          "headers": [
            { "name": "Accept", "value": "text/html" }
          ],
          "queryString": []
        },
        "response": {
          "status": 200,
          "statusText": "OK",
          "headers": [
            { "name": "Content-Type", "value": "text/html; charset=utf-8" }
          ],
          "content": {
            "size": 1256,
            "mimeType": "text/html",
            "text": "<!doctype html><title>Example</title>"
          }
        },
        "timings": { "blocked": 1, "dns": 12, "connect": 20, "send": 1, "wait": 80, "receive": 14 }
      },
      {
        "startedDateTime": "2026-09-22T12:00:00.200Z",
        "time": 45.2,
        "request": {
          "method": "GET",
          "url": "https://example.com/api/user",
          "headers": [
            { "name": "Accept", "value": "application/json" }
          ],
          "queryString": [
            { "name": "id", "value": "42" }
          ]
        },
        "response": {
          "status": 500,
          "statusText": "Internal Server Error",
          "headers": [
            { "name": "Content-Type", "value": "application/json" }
          ],
          "content": {
            "size": 54,
            "mimeType": "application/json",
            "text": "{\"error\":\"db timeout\"}"
          }
        },
        "timings": { "blocked": 0, "dns": -1, "connect": -1, "send": 1, "wait": 40, "receive": 4 }
      },
      {
        "startedDateTime": "2026-09-22T12:00:00.300Z",
        "time": 12.1,
        "request": {
          "method": "POST",
          "url": "https://example.com/api/login",
          "headers": [
            { "name": "Content-Type", "value": "application/json" }
          ],
          "queryString": []
        },
        "response": {
          "status": 401,
          "statusText": "Unauthorized",
          "headers": [
            { "name": "Content-Type", "value": "application/json" }
          ],
          "content": {
            "size": 31,
            "mimeType": "application/json",
            "text": "{\"error\":\"invalid token\"}"
          }
        },
        "timings": { "blocked": 0, "dns": -1, "connect": -1, "send": 2, "wait": 8, "receive": 2 }
      }
    ]
  }
}

Help Us Improve

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HAR file viewer & analyzer

HAR file analyzer online—open a .har, filter requests, inspect status and timings. Local-first. No signup.

What is a HAR file?

A HAR (HTTP Archive) file is a JSON log of browser network requests and responses—URLs, headers, status codes, timings, and bodies. A HAR file analyzer/viewer lets you open that export, filter entries, and inspect slow or failed requests. Use this free local-first tool to analyze HAR files online without uploading them.

What you can do here

Inspect HTTP Archive exports without installing extra software.

HAR file viewer: Open .har JSON and browse every captured request in a table.
HAR analyzer filters: Search URLs, filter by status class or HTTP method, and jump to failures.
Request detail panel: Inspect headers, query params, timings, and response text previews.
Local-first privacy: Analyze HAR files in the browser—no upload of cookies or auth tokens.

How to analyze a HAR file

From export to filtered insights.

Export a HAR
Capture traffic in Chrome/Firefox/Edge DevTools Network, then export .har.
Open it here
Drop the file or paste JSON into the HAR viewer.
Filter and inspect
Search, narrow by status/method, then open rows to read headers and timings.

Tips for HAR analysis

Find network bugs faster.

01
Filter 4xx/5xx first
Failed API calls often explain the bug before you dig into timings.
02
Watch wait vs receive
High wait usually means slow server/TTFB; high receive means large payloads.
03
Redact before sharing
HARs can include Authorization cookies—strip secrets before sending to teammates.
04
Preserve log when capturing
Enable Preserve log in DevTools so navigations do not wipe the export mid-repro.

Great for

When a HAR file analyzer helps.

Front-end debugging
Reproduce “works on my machine” network failures from a shared .har.
Performance triage
Spot slow endpoints and heavy assets from a single page load capture.
Support handoffs
Open customer-provided HAR files without installing desktop analyzers.

Why use this HAR analyzer

Fast local inspection of network archives.

Local-first
Sensitive HAR contents never leave the browser for this tool.
Free to use
Open and analyze HAR files with no signup.
Built for “har file” jobs
Viewer + filters + detail panel cover the usual analyze-and-debug loop.
No DevTools required to review
Teammates can inspect an exported .har without reproducing the session.

Technical notes

How this HAR viewer works.

Format: Supports HAR 1.2-style JSON with a top-level log.entries array (also accepts log as root).
Fields shown: Method, URL, status, MIME type, total time, body size, timings, headers, query string, text preview.
Response bodies: Text previews are truncated; base64 bodies are labeled rather than fully decoded.
Privacy: FileReader + JSON.parse only—no server upload for analysis.

Sources & References

HAR format and browser capture references.

“The HAR format is an archival format for HTTP transactions that can be used by a web browser to export detailed performance data.”
— W3C Web Performance — HTTP Archive format
HTTP Archive (HAR) format: Defines the JSON structure (log, entries, timings) this HAR analyzer parses. w3c.github.io/web-performance/specs/HAR/Overview.html
“Use the Network panel to log and inspect network activity, including exporting HAR files for sharing.”
— Chrome Developers — Network panel overview
Chrome DevTools — Network features: Documents how developers capture the HAR files you open in this viewer. developer.chrome.com/docs/devtools/network/
“The FileReader object lets web applications asynchronously read the contents of files stored on the user's computer.”
— MDN Web Docs — FileReader
MDN — FileReader: Used to load .har files entirely in the browser for local-first analysis. developer.mozilla.org/en-US/docs/Web/API/FileReader

Frequently Asked Questions

Quick answers about this tool—open a question to read more.

HAR file viewer & analyzer

What is a HAR file?

What you can do here

How to analyze a HAR file

Tips for HAR analysis

Great for

Why use this HAR analyzer

Technical notes

Sources & References

Frequently Asked Questions

CSV Viewer

Base64 Decode

CSV to JSON

Easings

Find and Replace