HAR File Analyzer & Waterfall

Analyze HAR entries locally with total request timing and DNS, connect, TTFB, and download phases. View a request timeline, filter by domain, content type, or status, inspect response bodies, and find slow or large requests. Import or drop a HAR file up to 100 MB; sensitive values are redacted in displayed details.

Har Analyzer · Client runtimeSandboxed

Har Analyzer Input

Har Analyzer Output

Formatted results will render here in real time.

Har Analyzer: JavaScript is required to run this tool in the browser.

About this har file analyzer & waterfall

API contract & interface schema logic

Summarizes request count, response body bytes, average total time, and status counts from HAR JSON. It does not calculate a waterfall or DNS, TLS, and TTFB phases.

Worked schema conversion scenario

Scenario: Review a HAR JSON summary without waterfall or timing-phase analysis.

Sample input:

{"log":{"entries":[{"time":12,"response":{"status":200,"bodySize":128}},{"time":20,"response":{"status":404,"bodySize":64}}]}}

Processing: Counts entries and response statuses, sums response.bodySize, and rounds the average entry time. It does not inspect URLs, DNS, TLS, TTFB, or a waterfall.

Illustrative output:

{ "entries": 2, "totalBodyBytes": 192, "averageTimeMs": 16, "statusCounts": { "200": 1, "404": 1 }, "missingBodySizeEntries": 0, "unknownBodySizeEntries": 0, "invalidBodySizeEntries": 0, "validTimeEntries": 2, "missingTimeEntries": 0, "invalidTimeEntries": 0 }

Schema version & syntax constraints

Requires log.entries to be an array. Missing bodySize and time are counted separately; bodySize -1 is unknown, other negative or nonnumeric values are invalid. Invalid or missing times are excluded from the average; with none valid it is null. No waterfall, DNS/TLS/TTFB, or slow-request diagnosis.

API specifications and schema models in HAR File Analyzer & Waterfall reflect OpenAPI and JSON Schema standards. Verify generated schemas against your runtime validator.

Client-side schema processing boundary

Schema analysis and protocol mapping in HAR File Analyzer & Waterfall execute locally in the browser tab without uploading endpoint definitions.

OpenAPI Specification & JSON Schema standards

OpenAPI Specification standards and JSON Schema draft definitions:

HAR 1.2 historical format reference (not a current W3C recommendation)

HAR File Analyzer & Waterfall verification · Audit standards

How to use it

Paste HAR JSON with log.entries.
Count entries and statuses, sum valid response body bytes, and average only valid nonnegative entry times.
Read the JSON summary.

Frequently asked questions

What does HAR Analyzer calculate?+

It requires HAR JSON whose log.entries is an array. It counts statuses, sums finite nonnegative bodySize values, and rounds the sum of finite nonnegative times divided by the number of valid time entries. With no valid times, averageTimeMs is null.

Can you show an input and its result?+

A two-entry HAR with body sizes 128 and 64 and times 12 and 20 produced 2 entries, 192 total body bytes, 16 average milliseconds, and status counts 200:1 and 404:1.

What HAR details are omitted?+

Missing bodySize is counted separately and not added; -1 is counted as unknown, while other negative or nonnumeric sizes are invalid. Missing time is counted separately; negative or nonnumeric time is invalid. These entries are excluded from the time average. Missing or non-array log.entries is an input error.

Can this summary diagnose network performance alone?+

No. It does not build a waterfall or diagnose performance; URLs, timing phases, transfer size, MIME, cache, redirects, HAR validity, capture conditions, and causes need separate evidence.