An introductory guide to general file recovery best practices, procedures, and some most popular file undelete / recovery tools.
Note: this article is still “work in progress” and it was originally split from the video recovery guide in order to make it more concise and easier to follow.
How To Recover Deleted or Damaged Files From Memory Card / PC Computer / Mobile Phone / Tablet
If you accidentally deleted your files or your battery run out before properly finishing the recording process, or if your computer or phone stopped responding, became frozen and/or auto rebooted during recording / capturing, recorded image or video file may be truncated (with damaged headers and abrupt ending) or it may not be visible on the storage medium at all (e.g. SD memory card or device’s internal memory storage), then it is time to perform a file recovery!
⚠️ First step in proper data recovery procedure is to copy damaged file(s) to another device or external disk, preferably a PC computer running Windows or other operating system. Of course, there are recovery tools available for Linux and Mac, however, we predominantly use Windows and many recovery tools that we’re gonna mention in this article run natively on Windows, but some of them can also be used on Linux and/or Mac/iOS and Android, or inside a Virtual Machine and/or Docker, which is beyond the scope of this guide.
So, first step is to take out memory card (SD card is most popular external storage card type today), insert it into memory card reader (built-in on many modern laptops or manually attach external USB card reader to PC) and than scan the memory card with tools such as Recuva, Get Data Back, PC Tools File Recover, File Undelete, DiskDigger, ZAR (Zero Assumption Recovery), PicaJet, PhotoRec, Transcend RecoveRx and so on. New tools appear on a daily basis and it is hard to keep track of them all.
From our experience, never trust only one app for the file system recovery stage! They basically scan TOC (Table of Content) tables and pointers on storage medium (SD card, USB flash memory, Hard Disk etc.) and search for continuous files. Different tools often report unrecoverable files, which may turn out as perfectly fine (or just mildly damaged but still playable), and some other tools may report perfectly healthy files, which are actually in ruins! In any case, if you don’t get positive results with one tool, don’t feel hopeless just yet – just give another tool a shot!
💡 But, here’s the trouble. With continuous development and increasing density in new generations of flash memory chips, mobile phones and tablets with built-in large 512 GB and 1 TB (1024 GB) are becoming easily available. There is no external memory card slot support available, and there is nothing to take out and attach to the PC, because storage memory chip is integrated directly onto the device itself!
Yes, internal storage is more secure, it prevents direct access to phone’s pictures and videos if stolen and locked with a strong PIN or password or pattern protection (we do not count special devices and software that can bypass these measures altogether), but it can also hurt the owner itself in cases such as this one. When you connect the phone or tablet with internal memory to the PC via USB cable, it is not mounted as a disk drive, but as an MTP (Media Transfer Protocol) device, which is a very limiting factor for any common file recovery tool available. In case of iPhone / iPad, external Mac and PC (Windows) tools actually scan device’s internal SQLite database to locate and recover deleted files, photos and videos, which is different beast altogether.
💡 PRO TIP
If you install File Explorer app on Android device (phone or tablet), you may see Main Storage and/or Internal Storage and/or SD Card memory locations available (later is usually present only in case your device supports external memory cards and you have one installed).
We say “usually” above, because depending on device’s brand, model, android version and file explorer app used, there can be some confusion about terminology here:
- “Main Storage” in File Explorer may actually refer to both device’s internal or external memory card (SD card), so be careful and check storage’s icon in File Explorer app to be sure
- “Internal Storage” usually refers to actual internal memory of your device
In case your device does not support external memory card, or you don’t have one installed, there will be only one storage available, regardless how it’s labelled (Main Storage or Internal Storage).
File path for internal storage usually looks like this on Android device:
File path for external memory card storage usually looks like this on Android device:
SD card storage location has this unique 8-digit string (grouped and concatenated into 2 groups of 4), so this is one easy way to be sure your files are on external storage location. You can check file location when you touch and hold any file (document, photo, video…) using file explorer app and select properties or info command.
In case you have a phone (or tablet) with no memory card slot present and used, the part of recovering a non-visible and non-accessible pictures and video file(s) can be very, very tricky procedure, next to impossible without some hacks, unless you have a rooted device (phone or tablet). Root access allows you to gain administrative privilege and perform a low-level scan of storage medium, bypassing operating system’s security layer.
💡 Some manufacturers allow you to unlock bootloader with their official tools. Then you can root your phone using some 3rd party or official rooting tools (if available). Keep in mind that rooted devices are inherently less secure, because if they get stolen or lost, they can potentially provide full access to all your data present on the device, including photos and videos.
Trouble is in the fact that user does not have a direct access to the internal storage memory itself in this case, but goes through another software / driver wrapper layer and storage is emulated. This is, unfortunately, true for many flagship Android models from Huawei, Xiaomi, OnePlus… but even if you have Samsung with SD card support, not all users actually buy extra storage and use it. They simply use the available internal memory for convenience since day one!
This is a very worrying and troubling trend from a damaged or deleted files recovery perspective TBH.
⚠️ Beware of fake/scatchy file recovery apps on Google Play store! Many recovery apps with high ratings claim to recover files, pretend to scan device’s internal and/or external storage not even bothering to warn that you need root (administrative) access, which is a red flag on its own, but they are nothing more than an ad serving portals with thousands of fake (purchased) reviews.
They do nothing to inform a user about root requirements and scanning process is vague (for example, there’s only a “file counter” at best, no feedback on current scanning folder location), but after a full scan they report back “deleted” files, which are, in fact, not deleted files at all. These app clones seriously damage honest and good ones that are few and far between and become lost in the crowd.
DiskDigger app for Android is one good app example that actually works and does what it claims. Root access is required for full scan of internal and external memory card storage! Free version supports images (photos / pictures / screenshots) and videos (root access is also required for video recovery!). Pro version is around $3 USD dollars, which is pretty affordable, and comes with added support for all other file types, including text documents, pdf, doc and alike. Regardless of which version you use (Free or Pro), in both cases, app can only access cached thumbnails and files on internal and/or external memory from certain folders and apps like Viber and WhatsApp if you do not have root privileges. Cache file(s) usually contain non-deleted smaller resolution versions of files which are located on your device (in order to speed up things like app view drawing, previewing, searching), but many times they also contain the ones deleted a very long time ago (depends on cache file age, your usage habits, and other factors). Both free and pro versions of DiskDigger can also access SD card storage, although, in that case you can also take your memory card out and put it into a dedicated card reader on your PC and use some other powerful recovery tools for Windows/Mac/Linux (in another words, you don’t have to root and mess with your phone device).
💡 When you recover your lost media files, it is wise NOT TO save them on the same memory location you are recovering them from! You may accidentally overwrite them during recovery procedure. Use external USB flash drive memory stick via USB OTG cable on your phone/tablet or use Google Drive, iCloud, FTP / local NAS storage or Email to save your recovered files, photos, videos on a remote location.
To be continued…