Migrate data of a Chrome extension from one computer to another

Question

I'm looking for how to migrate data of a Chrome extension from one computer to another. I'm not looking for migrating extension installation, but extension's stored data.

By data, I mean the normal user's data created through out the extension's usage. What I'm asking about is how to migrate this data, not the extension installation itself. Knowing that the data of the extension I'm trying to migrate isn't stored in the extension's folder existing in something like …\Profile 2\Extensions\eggkanocgddhmamlbiijnphhppkpkmkl. I'm not asking about migrating all the Chrome user's data, but the data of a single specific extension only.

— To here, my question is thoroughly described.

Below are question sections that may be helpful for progressing towards a solution.

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My specific use case:
I have Tabs Outliner Chrome extension. I have data stored on Computer 1. I copied all these files/folders from Computer 1 to Computer 2:

C:\Users\USERNAME\AppData\Local\Google\Chrome\User Data\Profile 2\IndexedDB\chrome-extension_eggkanocgddhmamlbiijnphhppkpkmkl_0.indexeddb.leveldb
C:\Users\USERNAME\AppData\Local\Google\Chrome\User Data\Profile 2\Sync Extension Settings\eggkanocgddhmamlbiijnphhppkpkmkl
C:\Users\USERNAME\AppData\Local\Google\Chrome\User Data\Profile 2\IndexedDB\chrome-extension_eggkanocgddhmamlbiijnphhppkpkmkl_0.indexeddb.blob
C:\Users\USERNAME\AppData\Local\Google\Chrome\User Data\Profile 2\databases\chrome-extension_eggkanocgddhmamlbiijnphhppkpkmkl_0

After doing this, I expected to find Tabs Outliner Computer 2 having the data that was in Computer 1. Instead, it gives me empty data as if I freshly installed the extension.

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Solution Suggestions I tried that didn't work:

▪ Suggestion #4: Calling chrome.storage.local.get(function(result){console.log(result)}) from console on the extension's page.

• It returned just a prototype, not the actual data object.

▪ Suggestion #3: Using Chrome Developer tools to access the local storage.

• Unfortunately it doesn't provide any feature to export/import the whole data set. It only enables the user to edit cells manually.

▪ Suggestion #2: Using below extensions trying to export Local Storage from Computer 1 then import on Computer 2.

• Storage Area Explorer, problem with it is that the export functionality isn't working, so I can't test it.

• LocalStorage Manager, problem with it is that it doesn't read Local Storage at all.

▪ Suggestion #1: Copying the extension's folder located in …\Profile 2\Extensions\eggkanocgddhmamlbiijnphhppkpkmkl from Computer 1 to Computer 2.

• It seems it doesn't contain the extension's data at all because the extension folder's size is very small.
• The solution was suggested by an answer to a question that seems duplicate to mine, but it's not, as it asks about installing chrome extension without the Google Web Store using offline files. While I'm asking about extracting the extension's data from one computer then copying it to another.

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Seems helpful hints:
▪ Hint #1: Tabs Outliner has data stored in local storage. I think if these local storage data is accessed from a file or somehow, if we copied it, then the job is done. (Hint inspirer: Suggestions 2 and 3)

▪ Hint #2: Tabs Outliner seems to have data stored in IndexedDB, as well, local storage.

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Answer 1

There are more directories for Chrome extension data in Windows. Organized by extension_id it is stored at these paths:

C:\Users\[user_name]\AppData\Local\Google\Chrome\User Data\Default\Local Extension Settings\[extension_id]

C:\Users\[user_name]\AppData\Local\Google\Chrome\User Data\Default\Sync Extension Settings\[extension_id]

C:\Users\[user_name]\AppData\Local\Google\Chrome\User Data\Default\IndexedDB\chrome-extension_[extension_id]

Copying files from/to extension directories may help depending on your extension structure. Not necessarily all three directories are populated/created (again this depends on extension behaviour).

Just inspect these and experiment.

Do a proper backup beforehand though!

Answer 2

As per your specific use case, the steps to migrate the 'Tabs Outliner' extension are outlined by the developer here (I have followed these instructions on a number of occasions, so I know that they work).

As explained in the link, the trick for a successful migration of the data is to first ensure that the extension is removed on the target Chrome. Then copy the data across. Then install the extension on the target Chrome. The extension should then use the migrated data.

This methodology also works for most other extensions, providing you a) know where the extension is storing the data and b) there are no specific customisations that will prevent it from working. Consequently, gaining details on data migration from the developer of the extension is best.

Due to the differing intricacies of data storage between extensions, it is often easier to simply copy the entire Chrome profile to the other computer, thereby preventing any problems. At the time of writing, I have successfully migrated a Chrome profile to another PC with Google Chrome, but when trying this with the Brave browser (v1.43.89 Chromium: 105.0.5195.102), it reset my settings and removed the extensions. It is possible that if I simply re-installed the extensions again in Brave, that the migrated extension data would then be used, but I didn't try this. So, just because it is possible to do one thing in Google Chrome, it doesn't mean that it is possible to do it in other, similar, browsers. Fortunately, it is possible to individually migrate the extension's specific data in Brave browser, as per this question.

Answer 3

How about this:

1. Back up your new system's User Data folder and keep the backup folder someplace safe.

2. Copy the old system's profile folder, or alternatively copy the entire User Data folder.

3. Move the copy of the old folder to somewhere on your new system, but don't replace the new system's existing folder.

4. Then run 'diff' to find the differences between the old system's folder and the new system's folder.

5. Copy the different files from the old system's folder into the corresponding folder on the new system.

Then see if it worked. (If it didn't, you can restore the new system's folder from the backup you created in step 1.)