This article compares

computer software Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work. At the lowest programming level, executable code consists ...

tools which are used for accomplishing comparisons of

files File or filing may refer to: Mechanical tools and processes * File (tool), a tool used to ''remove'' fine amounts of material from a workpiece **Filing (metalworking), a material removal process in manufacturing ** Nail file, a tool used to gent ...

of various types. The file types addressed by individual file comparison apps varies, but may include text, symbols, images, audio, or video. This category of software tool is often called "file comparison" or "diff tool", but those effectively are equivalent terms — where the term "diff" is more commonly associated with the

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

diff utility. A typical rudimentary case is the comparison of one file against another. However, it also may include comparisons between two populations of files, such as in the case of comparing directories or folders, as part of file management. For instance, this might be to detect problems with corrupted backup versions of a collection of files ... or to validate a package of files is in compliance with standards before publishing. Note that comparisons must be made among the same file type. Meaning, a text file cannot be compared to a picture containing text, unless an optical character reader (OCR) process is done first to extract the text. Likewise, text cannot be compared to spoken words, unless the spoken words first are transcribed into text. Additionally, text in one language cannot be compared to text in another, unless one is translated into the language of other. A critical consideration is how the two files being compared must be substantially similar and thus not radically different. Even different revisions of the same document — if there are many changes due to additions, removals, or moving of content — may make comparisons of file changes very difficult to interpret. This suggests frequent version saves of a critical document, to better facilitate a file comparison. A "diff" file comparison tool is a vital time and labor saving utility, because it aids in accomplishing tedious comparisons. Thus, it is a vital part of demanding comparison processes employed by individuals, academics, legal arena, forensics field, and other professional endeavors — to identify sometimes hard to spot differences needed for detecting. These uses include: * Revisions of texts, plans, or drawings. * Edit changes in media. * Omission of credit for quotes, citations, extracts, or exemplars. * Plagiarism. * Alteration of legal documents. *

Fraud In law, fraud is intentional deception to secure unfair or unlawful gain, or to deprive a victim of a legal right. Fraud can violate civil law (e.g., a fraud victim may sue the fraud perpetrator to avoid the fraud or recover monetary compen ...

. *

Forgery Forgery is a white-collar crime that generally refers to the false making or material alteration of a legal instrument with the specific intent to defraud anyone (other than themself). Tampering with a certain legal instrument may be forbi ...

. * Fakery, or " deepfake" to impersonate. * Disputes over ownership or credit for cooperative efforts. * Chronology of evolution of a project or effort. * Detect steganography (the practice of hiding data in plain sight). * Uncover removal of

watermark A watermark is an identifying image or pattern in paper that appears as various shades of lightness/darkness when viewed by transmitted light (or when viewed by reflected light, atop a dark background), caused by thickness or density variations ...

s. * Intentional defacement. * Identification of

graffiti Graffiti (plural; singular ''graffiti'' or ''graffito'', the latter rarely used except in archeology) is art that is written, painted or drawn on a wall or other surface, usually without permission and within public view. Graffiti ranges from s ...

tattoo A tattoo is a form of body modification made by inserting tattoo ink, dyes, and/or pigments, either indelible or temporary, into the dermis layer of the skin to form a design. Tattoo artists create these designs using several tattooing proc ...

, or other cultural mark with a signature style. * Unintentional or incidental damage. *Changes in health of living being. * Risk evaluation of propagation of structural damage. * Evaluation for restoration. * Degradation due to effects of environmental exposure over time, including natural

entropy Entropy is a scientific concept, as well as a measurable physical property, that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodyna ...

(decline over time): ** Oxidation. ** Rain exposure. ** Abrasion from wind-driven sand. ** Weathering from environmental changes in temperature, such as caused by freeze-thaw cycles. ** Fugitive (i.e. no permanent) pigments in paintings or printed materials from exposure to ultraviolet light. ** Exposure to vibration, such as industrial processes are from vehicular traffic.

General

Basic general information about file comparison software.

Compare features

API / editor features

Other features

Some other features which did not fit in previous table

Aspects

What aspects can be / are compared?

Time zone effects

When files are transferred across time zones and between Microsoft FAT and

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 f ...

file system In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one lar ...

s, the timestamp displayed by the same file may change, so that identical files with different storage histories are deemed different by a comparer that requires the timestamps to match. The difference is an exact number of quarters of an hour up to 95 (same minutes modulo 15 and seconds) if the file was transported across zones; there is also a one-hour difference within a single zone caused by the transition between standard time and

daylight saving time Daylight saving time (DST), also referred to as daylight savings time or simply daylight time (United States, Canada, and Australia), and summer time (United Kingdom, European Union, and others), is the practice of advancing clocks (typical ...

(DST). Some, but not all, file comparison and synchronisation software can be configured to ignore the DST and time-zone differences.Example: "Beyond Compare" help describes a user setting "timezone differences – ignores timestamp differences that are multiples of an exact hour." Software known to have daylight-saving compensation is marked in the Aspects table.

References

{{DEFAULTSORT:Comparison Of File Comparison Tools * File comparison tools