[Android Q&A, Help & Troubleshooting] Mr.Indigo:
What is your phone?

If is an Motorola, here is the tutorial:

Deodexing Explained + How To

So you want to theme… but you keep hearing about all this deodexing stuff… so whats that all about?

Stock android implements an odex file structure; for every (well…most) system app(s) (.apk file) and framework files (.jar) there is a corresponding .odex file, so for example you have;

/system/app/Phone.apk

/system/app/Phone.odex

/system/framework/com.motorola.android.mediasync.jar

/system/framework/com.motorola.android.mediasync.odex

What do the .odex files do?

All of your apps on your device are packaged as .apk files; these files are compiled from google source code and can interchangeably be viewed/thought of as a compressed folder (like a .zip or a .rar); and all of your framework components (well most…) are packaged as .jar files which literally stands for Java Archive (so again this can be compared to a .zip or a .rar).

When the android OS want’s to run your apps or utilize its framework components, it has to parse (read/interpret) the compressed data held within your .apk and/or.jar files. What the odex file structure aims to do, is to expedited this process by utilizing another file (.odex file) to compliment every.apk file (and .jar file); the odex file, includes the most critical data in an uncompressed format so the android os can quickly interpret that important information before parsing through the rest of the data held within the compressed .apk files (and .jar files). So subsequently, in an .odex file structure the .apk & .jar files don’t include all of the applications/framework-components data; Essentially, two files are acting as one; for your apps there are .apk files + their corresponding .odex file and for your framework components there are .jar files + their corresponding .odex file. This works nicely as an optimized file structure, except in the circumstance when the user want’s to theme; theming requires a modification to your .apks; the image files (.pngs) held within the pngs are replaced with different ones. However it is impossible to theme an application if it exists as two files. So that is why it is said you need to be DeOdexed in order to theme; DeOdexing is the process of re-bundling that uncompressed critical data (.odex files) back into your compressed .apk (& .jar) files, so that now all of the data is included in the .apk files necessary to run your applications without the presence of .odex files; in addition all the data is now included within the .jar files necessary to utilize your framework components without .odex files. In a DeOdexed file structure, there are no odex files present.

What are the benefit’s of DeOdexing?

Simple. To be able to theme a stock ROM.

Deodexing doesn’t speed your phone up or do anything of the sort.

It is simply something that is necessary to be able to theme a stock ROM.

How do you DeOdex?

One way you can deodex is to use the application xUltimate which actually rebundles that information for you. Another way, is to use a pre-made DeOdexer Update.zip; this zip already has all the repackaged fully compressed .apk files and utilizes code in the update script to delete all of the odex files present. So essentially all it’s doing is overwriting all your old semi data inclusive .apk files with fully inclusive ones and then deleting the (now) superfluous .odex files. This is the easiest way to do it, since all the work is already done for you. Just flash it in clockwork as you would for any theme:

Download it

Place it on your sdcard

Open Droid X Bootstrap

Hit Bootstrap Recover > Ok > Reboot Recovery

Navigate to ‘Install zip from sdcard’ with volume keys and select with camera button

Navigate to ‘Choose zip from sdcard’ and select

Navigate to the directory containing the above deodexer zip

Select it > Yes

Wait for it to do its thing > reboot system

You are now deodexed.

How can you check to see if you DeOdexed successfully?

Open a file explorer (like Root Explorer or Astro)

Navigate to the directory /system/app

Check for the presence of .odex files

Navigate to the directory /system/framework

Check for the presence of .odex files

If there are no odex files present then you are deodexed!

Now you can theme!

Will DeOdexing slow you down?

Technically it should, but in actuality its really quite negligible to notice, however… In my opinion, it’s rather silly to DeOdex and stay on stock ROM; you should just make the switch to a custom ROM. Why? Because custom ROMs are already deodexed and they zipalign your apps on boot; zipaliging is the process of reorganizing the manner in which the .apk is packaged to optimized it for being parsed faster by the android OS, it is comparable if not better than the odex file structure, so you get the best of both worlds; a themed ROM and the speed of an optimized file structure. That is why Stock is lame and custom ROMS pwn (IMO of course…)