Google Chrome Developer Tools : Android Debugging returns HTTP/1.1 404 Not Found. Why?

Question

This was working fine up until yesterday. Now when I connect my Android device for USB Debuggers. Chrome is no longer display my app.

Now the popup window shows HTTP/1.1 404 Not Found.

Looks to be connecting fine and the app runs fine on my Mobile Device.

Makeyevka

Note: this is because Chrome Developer Tools makes a request to the domain chrome-devtools-frontend.appspot.com, which fails, due to various reasons. – Virtue

Answer 1

Solution was to access through chrome://inspect/#devices

Then select the "inspect fallback" option.

This is because the remote browser was newer than the client browser.

Makeyevka

I don't see a fallback option. Can you provide more info please? i think this issue is due to today's chrome update for android – Gelid

This worked for me!! While the PC is connected to the device via USB with the app open, go to chrome://inspect/#devices on the PC. You should see the name of the app and an "inspect fallback" link – Rida

I don't have a fallback link but the same problem. It seems to be related to the latest Chrome update... (?!) Chrome Android Version: 68.0.3440.70, Chrome Desktop Version: 68.0.3440.75 – Cembalo

Issues have been created in Chromium Issue Tracker: bugs.chromium.org/p/chromium/issues/… bugs.chromium.org/p/chromium/issues/… – Cembalo

After downgrading my mobile chrome version to 67.x remote debugging works again. – Cembalo

Update mobile/tablet chrome browser if anyone can't see inspect fallback (Fallback) option – Ora

inspect link is showing but I only get 404 upon inspecting.. – Paule

In my case, just vice versa remote browser was older than the client browser. Remote version is: 90.0.4430.66 and client version is: 90.0.4430.72. Anyway, I don't see "inspect fallback" or any other deferent inspect. – Brouwer

Answer 2

Use VPN in both mobile and your computer.

It is maybe because of google restricted this feature in your country.

Boyla

Ridiculous but true! – Halhalafian

But I cannot use VPN on both cause I need to access my localhost on development machine, I used to get it work before don't know why this is happening now?! I use VPN on development machine and the issue was solved. – Dowable

for me I had to disable VPN – Zagreus

You are correct, when I switched to VPN on computer only and it works! But it only needs VPN when first and before click on inspect link, then you can stop VPN and refresh the DevTools without the error. – Depth

In my case I only had to use VPN on my computer – Prettypretty

@JavierLorenzo Me too – Crossruff

Answer 3

This problem just showed up on the latest released version of Chrome 72.0.3626.76 (will they ever add a regression test?).

None of these answers were completely satisfying.

• I was stuck with the same version on both Android and my desktop so "inspect fallback" is not showing on the UI.
• I tried to uninstall chrome from Android but that option is not available in Android 8.1?

Here is how you can workaround those issues and get back to debugging.

Workaround:

The objective of this workaround is to get the desktop version different than the device version so that you can see the inspect fallback option.

1. disable chrome updates. Instructions for Windows
2. uninstall latest Chrome on desktop.
3. install previous version: e.g. 71.0.3578.80 (using slimjet)
4. Open chrome://inspect/#devices url and choose inspect fallback instead of inspect.

Debugging restored!

Workaround 2:

As Asaf points out in the comments another way to get the versions to be different is to use the EDGE browser which is now based on Chromium. As long as the versions are different then the inspect fallback option should show up.

PS: I think this bug is still active in the canary channel so it may be a while before it gets fixed.

Here is the chromium bug.

UPDATE 3/6/2019

Looks like this is fixed again on version 72.0.3626.121 (maybe earlier builds)

Splanchnic

I use EDGE to get the inspect fallback, regular chrome 87 doesn't offer me this – Conventioneer

Now that EDGE is chromium based that is an effective workaround too as long as the EDGE version does not match your device version. – Splanchnic

Installing slimjet and debugging from that app worked for me! Thanks – Orthopedist

Answer 4

I have suffered this problem, cause the Google API has been blocked. If you are in mainland China, the GFW may be the reason. So, using VPN may be helpful.

Bookworm

Answer 5

Open https://chrome-devtools-frontend.appspot.com. If it returns 502, then it is maybe a host error.

Taeniafuge

For me this was the solution, as the chrome-devtools-frontend.appspot.com host was inaccessible from my machine. – Virtue

it returns me 404 – Paule

Answer 6

Just turn on your VPN if you are in a restricted country.

And don't tunnel your whole device so you can debug your web app over the network. Just use a chrome extension VPN.

Burnell

Answer 7

I did not have a fallback option at chrome://inspect/#devices, but I was able to fix it by uninstalling chrome updates on my Android device, as this is caused by the most recent update for android's chrome.

Go to Chrome's App Info, press the 3 dots in the top right corner and then click uninstall updates.

Gelid

Answer 8

In my case it was because port 8080 was not enabled

1. open link chrome://inspect/#devices
2. select "Port Forwarding"
3. add "localhost:8080"

Stupefacient

Answer 9

Got around this by disabling Chrome on my phone, the latest version has a bug. This forces your app to use the webview version that shipped with your phone.

Sexpot

Answer 10

I have a similar problem, where the inspect fallback link doesn't appear, if the host version is newer than the guest version. In my case, I'm using Vivaldi to debug another browser. However this still gives the above mentioned error:

HTTP/1.1 404 Not Found

Installing different browser versions is cumbersome and unncessary. In my current browser, break in the page chrome://inspect/#devices's inspect.js where it says:

const browserNeedsFallback =
    isVersionNewerThanHost(browser.adbBrowserVersion);

Run the snippet:

isVersionNewerThanHost = () => true

And the inspect fallback link will appear again.

Harpist

Confirming, this indeed works. What are you hacking your dev tools with obwiously with the dev tools :) – Twyla

Answer 11

i have updated to the latest desktop chrome version and now it works. not having white screen anymore. my current version : Version 73.0.3683.75 (Official Build) (64-bit).

i forgot to note down my previous version so i can't

Marrin

Answer 12

Solved the issue uninstalling Chrome updates on my phone by following answer above: pressing the 3 dots in the top right and then clicking uninstall updates.

Cheongsam

Answer 13

Another solution is to use Chrome Beta instead of Chrome on your mobile device. It has the Inspect Fallback option on version 97.0.4692.20

Mimamsa

Answer 14

If you live in Iran or a country that this feature is restricted , You better off using Firefox remote debugging , it misses port forwarding feature right now , but at least works like a charm.

Devest

Answer 15

For many people who still having this issue, if you are in your company's VPN/ Network try to connect directly to the internet and it will work. For me it happened that our IP address were blocked by Google and any of google services were accessible.

Incontinent

Answer 16

Had the same problem. I had been working with the inspect fallback option but it wasn't available anymore. I went to the play store and updated chrome. Now the inspect fallback option is available and it works when I select it

Goodspeed

Answer 17

I uninstall chrome in my movil and work ok..the problem is the last update chrome in android

Spectatress

Answer 18

I found a solution. Don't need to downgrade you Chrome version. just remove a plugin. This plugin is for the VPN proxy. Yes. Maybe the issue is caused by a plugin.

Beluga

Answer 19

I had the same problem. I had to reset the phone to factory defaults. now working. Android 6

Necrophilism

do not do this. go to app info for chrome, and click uninstall updates. this does the same thing, and you get to keep all of your data. – Gelid