HLS HAR Analyzer

A tool to help debug HAR captures of HLS streams playing back.

Getting started

Install the analyzer with npm:

npm install hls-har-analyzer

then startup the server using the start script:

npm start

Now you can load up the analyzer in your browser by visiting http://localhost:7777.

What's it good for?

Live streaming is really hard to debug. If you're not the one experiencing the problem, how do you collect enough information from your viewers to fix an issue? A common technique is to capture an HTTP Archive (or HAR file) from someone who can reproduce that issue and then send it to an expert for analysis. There are generic tools out there for visualizing HAR files but it can take a lot of work to dig out the important pieces from a log of all captured traffic.

The HLS HAR analyzer is designed to filter out only the requests related to playback of HLS video. It allows you to quickly review the requests related to HLS playback and will even decrypt TS segments if all of the necessary info is available in the capture. If you're the expert called in to diagnosis a live streaming problem, hopefully it saves you from a bunch of manual steps and lets you identify issues faster.

Using the analyzer

Once you have the server running, open the main page in a modern browser of your choice. Use the input form at the top to upload your HAR file and then you'll see a table like this:

From here, you can:

• Examine responses: click on a file name to download it (or open it in a browser window) directly. If it's a TS segment that appears to be encrypted, you can click the "decrypted" link to download a clear version of the segment.
• Replay the session: copy the m3u8 link at the top of the results area into a player to see a replay of the sequence of segments from the capture. You can use the text fields at the top of the results to filter the segments that appear in the replay m3u8.