This is a list of

file format A file format is a standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary or free. Some file formats ...

s used by archivers and

compressor A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor. Compressors are similar to pumps: both increase the pressure on a fluid and both can transp ...

s used to create

archive files In computing, an archive file is a computer file that is composed of one or more files along with metadata. Archive files are used to collect multiple data files together into a single file for easier portability and storage, or simply to compres ...

Archiving only

Compression only

Archiving and compression

Data recovery

Comparison

Containers and compression

Notes

While the original

tar Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. "a dark brown or black bit ...

format uses the

ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of ...

character encoding, current implementations use the

UTF-8 UTF-8 is a variable-width encoding, variable-length character encoding used for electronic communication. Defined by the Unicode Standard, the name is derived from ''Unicode'' (or ''Universal Coded Character Set'') ''Transformation Format 8-bit'' ...

(Unicode) encoding, which is backwards compatible with ASCII.
Supports the external Parchive program (par2).
From 3.20 release RAR can store modification, creation and last access time with the precision up to 0.0000001 second (= 0.1 µs)

br /> The PAQ family (with its lighter weight derivative LPAQ) went through many revisions, each revision suggested its own extension. For example: ".paq9a".
WIM can store the

ciphertext In cryptography, ciphertext or cyphertext is the result of encryption performed on plaintext using an algorithm, called a cipher. Ciphertext is also known as encrypted or encoded information because it contains a form of the original plaintext ...

of encrypted files on an

NTFS New Technology File System (NTFS) is a proprietary journaling file system developed by Microsoft. Starting with Windows NT 3.1, it is the default file system of the Windows NT family. It superseded File Allocation Table (FAT) as the preferred fil ...

volume, but such files can only by decrypted if an administrator extracts the file to an NTFS volume, and the decryption key is available (typically from the file's original owner on the same Windows installation). Microsoft has also distributed some download versions of the Windows operating system as encrypted WIM files, but via an external encryption process and not a feature of WIM. *Purpose: Archive formats are used for backups, mobility, and

archiving An archive is an accumulation of historical records or materials – in any medium – or the physical facility in which they are located. Archives contain primary source documents that have accumulated over the course of an individual or ...

. Many archive formats

compress compress is a Unix shell compression program based on the LZW compression algorithm. Compared to more modern compression utilities such as gzip and bzip2, compress performs faster and with less memory usage, at the cost of a significantly l ...

the data to consume less storage space and result in quicker transfer times as the same data is represented by fewer bytes. Another benefit is that files are combined into one archive file which has less overhead for managing or transferring. There are numerous

compression algorithms In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression ...

available to losslessly compress archived data and some algorithms work better (smaller archive or faster compression) with particular data types. Archive formats are also used by most operating systems to package software for easier distribution and installation than

binary executables In computing, executable code, an executable file, or an executable program, sometimes simply referred to as an executable or binary, causes a computer "to perform indicated tasks according to encoded instructions", as opposed to a data file ...

. *Filename extension: The

DOS DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems. DOS may also refer to: Computing * Data over signalling (DoS), multiplexing data onto a signalling channel * Denial-of-service attack (DoS), an attack on a communicat ...

and

Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

operating systems required filenames to include an extension (of at least one, and typically 3 characters) to identify the file type and use. Filename extensions must be unique for each type of file. Many

operating systems An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also inc ...

identify a file's type from its contents without the need for an extension in its name. However, the use of three-character extensions has been embraced as a useful and efficient shorthand for identifying file types. *Integrity check: Archive files are often stored on

magnetic media Magnetic storage or magnetic recording is the storage of data on a magnetized medium. Magnetic storage uses different patterns of magnetisation in a magnetizable material to store data and is a form of non-volatile memory. The information is ac ...

, which is subject to

data storage Data storage is the recording (storing) of information (data) in a storage medium. Handwriting, phonographic recording, magnetic tape, and optical discs are all examples of storage media. Biological molecules such as RNA and DNA are conside ...

errors. Early tape media had a higher rate of errors than they do today. Many archive formats contain extra error-correction information to detect storage or transmission errors, and the software used to read the archive files contains

logic Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of logical truths. It is a formal science investigating how conclusions follow from premises ...

to detect and possibly correct errors. *Recovery record: Many archive formats contain redundant data embedded in the files in order to detect data storage or transmission errors, and the software used to read the archive files contains logic to detect and correct errors. *Encryption: In order to protect the data being stored or transferred from being read if intercepted, many archive formats include the capability to encrypt the data. There are multiple mathematical algorithms available to encrypt data.

Software packaging and distribution

Notes

Not to be confused with the archiver

JAR A jar is a rigid, cylindrical or slightly conical container, typically made of glass, ceramic, or plastic, with a wide mouth or opening that can be closed with a lid, screw cap, lug cap, cork stopper, roll-on cap, crimp-on cap, press-on c ...

written by Robert K. Jung, which produces ".j" files.

Features

Notes

Compression is not a built-in feature of the formats, however, the resulting archive can be compressed with any algorithm of choice. Several implementations include functionality to do this automatically
Most implementations can optionally produce a self-extracting executable
Per-file compression with

gzip gzip is a file format and a software application used for file compression and decompression. The program was created by Jean-loup Gailly and Mark Adler as a free software replacement for the compress program used in early Unix systems, and in ...

, bzip2, lzo, xz, lzma (as opposed to compressing the whole archive). An individual can choose not to compress already compressed filenames based on their suffix as well.

Footnotes

{{DEFAULTSORT:Archive Formats Lists of file formats *

Archiving only

Compression only

Archiving and compression

Data recovery

Comparison

Containers and compression

Notes

Software packaging and distribution

Notes

Features

Notes

See also

Footnotes