ZIP and RAR two popular archive file formats which support lossless data compression. They both can contain your data and files in a compressed form, so you can get more free space on your hard disk drive. Unfortunately, any of these archive files are not immune to corruption like other computer files. You can’t extract anything from a corrupt archive file. You must repair ZIP file or RAR file, so that you can extract your data. In this blogpost, we’ll read about two different solutions to repair archive files like ZIP and RAR.
File & Data Compression – Its Types
File compression, aka data compression, refers to a method or a process of compressing the files by reducing their size in order to save more free space on a hard disk. Unlike uncompressed files, if the files are compressed, they significantly take less storage space on your storage device, be it system hard disk or any external storage media like USB drive. Generally there are two main types of compression: lossless and lossy, and both are different from each other. How?
Lossless Compression: The algorithms of lossless compression search for long strings of code, so that they can be replaced with shorter strings. It can recreate the entire file exactly same as it was before compression.
Lossy Compression: The algorithms of lossy compression search through the code in order to find the pieces which you can delete. It actually reduces the file size by permanently eliminating certain information, especially redundant information.
Benefits of File Compression
- File compression can easily reduce the amount of space needed for data storage;
- File compression can be used for any type of computer files;
- Data transfer speed can be increased by file compression;
- You can reduce the disk space on Internet server by file compression;
- File compression also provides data security;
Types of Compressed Files or Archives
There are different types of compressed files or archives used by computer users, such as: ZIP, RAR, TAR, TAR.Gz and 7z.
ZIP is the most popular compressed cum archive file format created by WinZip and WinRAR utilities. It contains one or multiple files in compressed form. In a ZIP archive, files are stored separately from each other and compressed by using different methods. You can extract files from a ZIP archive without compressing or decompressing the entire archive.
RAR is also an archive cum compressed file format just like ZIP. It uses RAR compression to compress one or multiple files. RAR archive is created by WinRAR which uses a higher compression ratio than ZIP compression. You can extract data from RAR archive by using a variety of programs.
TAR is an archive file format created by TAR utility, a Unix-based utility for packaging multiple files together in uncompressed form. The TAR utility creates an archive which contains a large number of files. Unlike other archive file formats, it doesn’t compress the files.
TAR.Gz is a TAR archive compressed with the standard GNU-ZIP (gzip) compression algorithm. A TAR.Gz file can contain one or more compressed files. It includes both TAR and Gz file types. It’s commonly used in Unix operating systems for packaging files, programs and installers. To open or use TAR.Gz archive, first you must decompress it and then expand it by using TAR utility.
7z is a compressed archive file format created by 7-Zip compression utility. Though users don’t often use this archive format, but it’s much better than other formats. It uses an open-source LZMA aka Lempel–Ziv–Markov chain algorithm compression which provides high compression ratio and strong AES-256 (256-bit) encryption. A 7z archive file can be up to 16,000,000,000 GB of size. Other than LZMA (by default), 7z supports PPMD, BCJ, BCJ2, BZip2, and Deflate compression methods.
Though file compression provides you vast benefits, but a compressed file is prone to corruption like every other computer file. There are numerous reasons which are highly responsible for corruption in archive files, such as: virus attack, sudden power outage, abruptly system shutdown, hard disk crash or failure, interrupted Internet connection during uploading or downloading archive file, software malfunction or failure, and many more.
How to repair ZIP file and/or RAR file?
The best thing you can use to repair ZIP file or repair RAR file is WinRAR application. It has a built-in repair feature that can repair corrupt archive and open it. You just need to follow the steps (shown below)
Step 5: Again a small window “Repairing File name.zip” will pop up.
Click Browse to select a location to save the repaired archive. Also, define the archive type before you can start the repairing process. For e.g. if you want to repair ZIP file, check Treat the corrupt archive as ZIP, or check Treat the corrupt archive as RAR to repair RAR file. Click OK.
You can now check your repaired archive file.
Data Extraction from Corrupt Archive File
There’s one more thing you can do here manually to repair ZIP file or RAR file. But make sure the corrupt ZIP or RAR archive doesn’t contain large software’ executable files. If you’re having multiple image, audio, video, email, document and other types of files, you can try this trick before purchasing any paid software to repair ZIP file.
Step 4: Click OK to begin the data extraction process. This will extract all the files from the corrupt archive.
Note: You can only extract those files which are not broken or corrupt.
Professional Solution – Archive Recovery Software
If the above manual trick fails or doesn’t work, then you need to try a professional recovery solution. There are many software companies in the market which provide 3rd party ZIP recovery and RAR recovery tools. You can try few of them. Or you can download free demo version of Archive Recovery software. This software doesn’t only support only one or two archive formats. In fact, it supports all 5 popular archive cum compressed file formats, such as: ZIP, RAR, TAR, TAR.gz and 7z. You must download its demo version for free evaluation. You can check the preview of recovered data in demo version. To save them, you’ll need its licensed version.