# Remote Debugging

**URL:** <https://discourse.mozilla.org/t/remote-debugging/54163>\
**Category:** Developer Tools\
**Created:** [February 17, 2020, 11:13am UTC](https://discourse.mozilla.org/t/remote-debugging/54163 "2020-02-17T11:13:37Z")\
**Posts on this page:** 16\
**Page:** 1

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**Author:** ![knutsford-software](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/knutsford-software/32/34271_2.png) [@knutsford-software](https://discourse.mozilla.org/u/knutsford-software)\
**Post date:** [February 17, 2020, 11:13am UTC](https://discourse.mozilla.org/t/remote-debugging/54163/1 "2020-02-17T11:13:38Z")

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I want to be able to debug a site on my Samsung Galaxy A6 remotely. My phone has been found on the left under about:debugging#/setup but it is stuck on “waiting for browser” and I have no idea why. Thanks

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**Author:** ![jdescottes](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/jdescottes/32/22185_2.png) [@jdescottes](https://discourse.mozilla.org/u/jdescottes)\
**Post date:** [February 17, 2020, 11:39am UTC](https://discourse.mozilla.org/t/remote-debugging/54163/2 "2020-02-17T11:39:53Z")

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Hi @knutsford-software!

Which browser do you want to debug? I assume Firefox Preview?  
If this is the case, try opening a tab on Firefox Preview, sometimes the browser doesn’t become available until a tab is open.

I had a bug filed to improve this: [https://bugzilla.mozilla.org/show\_bug.cgi?id=1561284](https://bugzilla.mozilla.org/show_bug.cgi?id=1561284) but I didn’t get to it yet.

Let us know how it goes!  
Julian

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**Author:** ![knutsford-software](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/knutsford-software/32/34271_2.png) [@knutsford-software](https://discourse.mozilla.org/u/knutsford-software)\
**Post date:** [February 17, 2020, 11:50am UTC](https://discourse.mozilla.org/t/remote-debugging/54163/3 "2020-02-17T11:50:36Z")

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I had spotted that bug when I was googling. I am glad I am not the only one with the problem. I don’t really mind which browser I use as long as I can debug JavaScript and Jquery. I just searched for Firefox in finder on my phone so I am guessing that is FireFox Preview. I tried Chrome and my Chrome brower on my Desk top but in taht case it didn’t find my Phone

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**Author:** ![jdescottes](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/jdescottes/32/22185_2.png) [@jdescottes](https://discourse.mozilla.org/u/jdescottes)\
**Post date:** [February 17, 2020, 12:06pm UTC](https://discourse.mozilla.org/t/remote-debugging/54163/4 "2020-02-17T12:06:25Z")

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Great! make sure you use Firefox Preview. The old “Firefox for Android” is based on a very old Firefox version and will not work for remote debugging (it should be replaced by Firefox Preview soon).

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**Author:** ![knutsford-software](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/knutsford-software/32/34271_2.png) [@knutsford-software](https://discourse.mozilla.org/u/knutsford-software)\
**Post date:** [February 17, 2020, 12:07pm UTC](https://discourse.mozilla.org/t/remote-debugging/54163/5 "2020-02-17T12:07:23Z")

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opening a new tab didn’t make any difference. Is there was way of JavaScript debugging via the actual mobile? I gather there isn’t.

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**Author:** ![knutsford-software](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/knutsford-software/32/34271_2.png) [@knutsford-software](https://discourse.mozilla.org/u/knutsford-software)\
**Post date:** [February 17, 2020, 12:11pm UTC](https://discourse.mozilla.org/t/remote-debugging/54163/6 "2020-02-17T12:11:08Z")

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Ah - do I need to download FireFox Preview on my Phone then?

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**Author:** ![jdescottes](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/jdescottes/32/22185_2.png) [@jdescottes](https://discourse.mozilla.org/u/jdescottes)\
**Post date:** [February 17, 2020, 12:22pm UTC](https://discourse.mozilla.org/t/remote-debugging/54163/7 "2020-02-17T12:22:04Z")

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Yes, that’s the best solution here.

The old Firefox For Android has “remote debugging” disabled by default (that’s why it doesn’t show up in the sidebar). As mentioned in [https://developer.mozilla.org/en-US/docs/Tools/about:debugging](https://developer.mozilla.org/en-US/docs/Tools/about:debugging) , you have to enable USB remote debugging in the advanced settings of the application. But as I said, it’s too old to be used with your current Firefox Desktop, so try to use Firefox Preview instead.

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**Author:** ![knutsford-software](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/knutsford-software/32/34271_2.png) [@knutsford-software](https://discourse.mozilla.org/u/knutsford-software)\
**Post date:** [February 17, 2020, 12:25pm UTC](https://discourse.mozilla.org/t/remote-debugging/54163/8 "2020-02-17T12:25:09Z")

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Still not working with preview either ☹ Even with a new tab

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**Author:** ![jdescottes](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/jdescottes/32/22185_2.png) [@jdescottes](https://discourse.mozilla.org/u/jdescottes)\
**Post date:** [February 17, 2020, 12:33pm UTC](https://discourse.mozilla.org/t/remote-debugging/54163/9 "2020-02-17T12:33:19Z")

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I just checked and USB debugging is also disabled by default on Firefox Preview. Can you open the settings of Firefox Preview ("…" menu on the bottom-right) and check if Remote USB Debugging is on or off?

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**Author:** ![knutsford-software](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/knutsford-software/32/34271_2.png) [@knutsford-software](https://discourse.mozilla.org/u/knutsford-software)\
**Post date:** [February 17, 2020, 2:52pm UTC](https://discourse.mozilla.org/t/remote-debugging/54163/10 "2020-02-17T14:52:27Z")

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Brilliant - thanks. That worked

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**Author:** ![jdescottes](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/jdescottes/32/22185_2.png) [@jdescottes](https://discourse.mozilla.org/u/jdescottes)\
**Post date:** [February 17, 2020, 4:01pm UTC](https://discourse.mozilla.org/t/remote-debugging/54163/11 "2020-02-17T16:01:25Z")

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Thanks for updating us, glad it works now!

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**Author:** ![knutsford-software](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/knutsford-software/32/34271_2.png) [@knutsford-software](https://discourse.mozilla.org/u/knutsford-software)\
**Post date:** [February 17, 2020, 4:18pm UTC](https://discourse.mozilla.org/t/remote-debugging/54163/12 "2020-02-17T16:18:37Z")

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So am I. It didn’t display any JQuery errors unfortunately . I was hoping it might give me a clue why a slider won’t drag if you look on a mobile. O well it will be usefull for another time

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**Author:** ![digitarald](https://avatars.discourse-cdn.com/v4/letter/d/c77e96/32.png) [@digitarald](https://discourse.mozilla.org/u/digitarald)\
**Post date:** [February 17, 2020, 11:35pm UTC](https://discourse.mozilla.org/t/remote-debugging/54163/13 "2020-02-17T23:35:06Z")

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Glad remote debugging worked out. Might be useful to highlight further which browsers can be debugged.

Does your slider problem reproduce using the Responsive Design Mode on desktop?

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<div class="post-metadata">

**Author:** ![knutsford-software](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/knutsford-software/32/34271_2.png) [@knutsford-software](https://discourse.mozilla.org/u/knutsford-software)\
**Post date:** [February 18, 2020, 9:19am UTC](https://discourse.mozilla.org/t/remote-debugging/54163/14 "2020-02-18T09:19:49Z")

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Yes it does. Does that explain the problem? Is it CSS somehow then as I suspect.

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<div class="post-metadata">

**Author:** ![knutsford-software](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/knutsford-software/32/34271_2.png) [@knutsford-software](https://discourse.mozilla.org/u/knutsford-software)\
**Post date:** [February 18, 2020, 9:29am UTC](https://discourse.mozilla.org/t/remote-debugging/54163/15 "2020-02-18T09:29:16Z")

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If I disable the Touch Simulation it works and you can drag the slider

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<div class="post-metadata">

**Author:** ![knutsford-software](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/knutsford-software/32/34271_2.png) [@knutsford-software](https://discourse.mozilla.org/u/knutsford-software)\
**Post date:** [February 18, 2020, 9:34am UTC](https://discourse.mozilla.org/t/remote-debugging/54163/16 "2020-02-18T09:34:40Z")

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Ah - [https://stackoverflow.com/questions/13808663/jquery-ui-slider-touch-drag-drop-support-on-mobile-devices?answertab=votes#tab-top](https://stackoverflow.com/questions/13808663/jquery-ui-slider-touch-drag-drop-support-on-mobile-devices?answertab=votes#tab-top)

Thanks for mentioning Responsive Design Mode - I hadn’t realised it existed. That will be very useful