Save all voicebox messages from your FRITZ!Box 7530 router

My parents’ FRITZ!Box 7530 (FRITZ!OS version 7.57) voicebox had “filled up” and before clearing all messages I was looking for a way to download all of them as a backup.

There is no really convenient way to do this in the web UI (there were close to 200 messages, some dating back more than 4 years), so I resorted to JavaScript to print a list of curl commands to download each message as a .wav file.

Messages are listed in a table with the following format:

<tr class="thead">
    <th class="sortable"></th>
    <th class="sortable sort_by_date">Date<span class="sort_no">&nbsp;</span></th>
    <th class="sortable">Name/Number<span class="sort_no">&nbsp;</span></th>
    <th class="sortable">Your Number<span class="sort_no">&nbsp;</span></th>
    <th class="sortable">Duration<span class="sort_no">&nbsp;</span></th>
    <td class="newicon" datalabel="28.12.23 16:00">&nbsp;</td>
    <td>28.12.23 16:00</td>
    <td datalabel="Name/Number">Caller's Name</td>
    <td datalabel="Your Number">1234</td>
    <td datalabel="Dauer">&lt; 1 Min</td>
    <td class="btncolumn" datalabel="">
        <button type="submit" class="icon fon_book" id="" name="" value="" title="" disabled=""><img src="/assets/icons/ic_fonbook_add.svg" alt=""></button>
        <a class="download icon" href="/cgi-bin/luacgi_notimeout?sid=<session uuid>&amp;script=%2Flua%2Fphoto.lua&amp;myabfile=%2Fdata%2Ftam%2Frec%2F<recording id>">
            <button type="submit" class="icon audio" id="play_1" name="play" value="1" title="Play message/Save">
                <img src="/assets/icons/ic_triangle_right_blue.svg" alt="Play message/Save">
            <audio preload="auto"></audio>
        <button type="submit" class="icon delete" id="delete_1" name="delete" value="1" title="Delete"></button>

We want to ignore the header row and for every subsequent row, get the date and the caller’s name or number, to build a meaningful file name for the to-be-downloaded .wav file, and the URL of the link. The link points to a script that emits the raw WAV audio as a binary stream.

This is a quick & dirty piece of JavaScript to paste into the JavaScript console of Chrome’s Developer tools (keyboard shortcut Ctrl-Shift-I) to generate a list of curl invocations to download each message with a useful file name:

console.log(Array.from(document.querySelectorAll('table#uiTamCalls tr:not(.thead)')).map(e => {
    return `curl -s -o "${e.childNodes[1].innerText} ${e.childNodes[2].innerText}.wav" '${e.querySelector('a').href}'`;

My initial attempt was downloading the file via the browser by invoking .click() on each link, however that turned out to work less well as Chrome doesn’t really like downloading files over a non-secure connection, requires you to allow multiple simultaneous downloads via a popup box and even if you do, will only download 10 files at a time.

YMMV if you have a different FRITZ!Box model or FRITZ!OS version, however I’d expect a similar approach should still work.

About the author:

Site Reliability Engineer at Google in Zürich, Switzerland. Former Computational Scientist at ECMWF in Reading, UK. PhD from Imperial College. Public speaker. Feminist. Pythonista. Cyclist. Open source contributor & maintainer. Hobbyist photographer. PyData London co-founder.