mp3cut.net - Unsupported feature using Firefox

[webcompat-bot]

URL: https://mp3cut.net/es/

Browser / Version: Firefox 100
Operating System: Windows 11
Tested Another Browser: Yes Firefox

Problem type: Something else
Description: Audio pitch dont work in Firefox Browser marked as an "old" Browser
Steps to Reproduce:
This website allow you to edit mp3 files and change many paramenter one of them are the audio pitch, this work on any Chromium web browser but not on Firefox. they say "This browser dont support this feature"

View the screenshot

Browser Configuration

• None

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[softvision-raul-bucata]

We appreciate your report. I was able to reproduce the issue. Attempting to change the audio playback speed by clicking on the "Velocidad" button returns an unsupported browser message:

Tested with:

Browser / Version: Firefox Release 100.0 (64-bit)/ Firefox Nightly 102.0a1 (2022-05-04) (64-bit) /Chrome Version Version 101.0.4951.54 (Official Build)
Operating System: Windows 10 PRO x64

Notes:

1. Reproducible regardless of the status of ETP.
2. Reproducible on the latest build of Firefox Nightly.
3. Works as expected using Chrome:

Moving this to NeedsDiagnosis for further investigations.

[qa_18/2022]

[reinhart1010]

Possibly a Firefox 100 issue

[wisniewskit]

It does seem to work fine if I spoof the user-agent string to a Chrome one. I would guess that they probably ran into a long-since-fixed bug (perhaps https://bugzilla.mozilla.org/show_bug.cgi?id=1383363) with Firefox which made them want to disable the feature, and they never re-enabled it later.

Their code does this check for their "atempo" feature:

        supported: function () {
          return !Ye.isFirefox && !Ye.isSafari
        },

Which rather unfortunately just boils down to this check:

e.isFirefox = function () {
      return !o.default.prototype.$isServer && !!window.navigator.userAgent.match(/firefox/i)
    }

So we would need to spoof the JS useragent string to not include the string "firefox" to work around this in an intervention.

[webcompat-bot]

Generate outreach template

[karlcow]

This is happening on Safari too.

[wisniewskit]

This is now working for me on Firefox and Safari, so it appears that the site has fixed this issue. Thanks to their devs!