Comparison of file comparison tools

This article compares computer software tools that are used for accomplishing comparisons of files 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 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.
  • Forgery.
  • 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 watermarks.
  • Intentional defacement.
  • Identification of graffiti, tattoo, 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 (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 edit

Basic general information about file comparison software.

Name Creator FOSS Free First public release date Year of latest stable version Windows Macintosh Linux Other platforms Max supported file size
Beyond Compare Scooter Software[1] No; Proprietary No 1996 2023-10-19 (v4.4.7) Yes Yes Yes > 2GB (64 bits)
Compare++ Coode Software[2] No; Proprietary No 2010 2016-7-17 (3.0.1.0b) Yes[3] No No
diff, diff3 AT&T Yes; BSD 3-clause, BSD 4-clause, CDDL, GPL, Proprietary Yes 1974 No Yes (Mac OS X) Yes ported to most platforms as part of SCCS > 2GB but less than 64 bits
Eclipse (compare) Yes; Eclipse Public License Yes 2004-07-21 2016-09-28 (4.6.1 (Neon.1)) Yes Yes Yes Anything with Java
Ediff Michael Kifer[4] Yes; GPL Yes 1994 2.81.4 Yes[a] Yes (Mac OS X) Yes Anything with Emacs and diff
ExamDiff Pro PrestoSoft[5] No; Proprietary No 1998 2022-06-04 (v 12.0.1.22) Yes (WinXP and up) No No
Far Manager (compare) Eugene Roshal (original); FAR Group Yes; Revised BSD license Yes 1996 2022-02-02 (v3.0 build 5959) Yes No No There's a beta-version of far2l,[6] a Linux fork of FAR Manager v2 which also works on OSX/MacOS and BSD.
fc Microsoft[7] No; Proprietary Yes; Part of OS 1987 Yes (DOS) No No
FileMerge (aka opendiff) Apple Inc. No; Proprietary Yes; (part of Apple Developer Tools) 1993 (part of NEXTSTEP 3.2[8]) 2014 (v2.8) No Yes (Mac OS X) No
FreeFileSync[data missing] Zenju Yes; GPLv3 Yes 2008 2023-10-23 (v13.2) Yes Yes Yes
Guiffy SureMerge Guiffy Software[9] No; Proprietary No 2000 2023-05-02 (v12.2) Yes Yes Yes Anything with Java > 2GB
IntelliJ IDEA (compare) JetBrains[10] No; Proprietary No 2001 2019-08-20 (2019.2.1) Yes Yes Yes
jEdit JDiff plugin Various[11] Yes; GPL Yes 1998 2020-09-03 (5.6.0) Yes Yes Yes Anything with Java
Lazarus Diff Lazarus (software) Yes; GPL Yes 2000 2020-07-11 (2.0.10) Yes Yes Yes FreeBSD
Meld Stephen Kennedy[12] Yes; GPLv2+ Yes 2002 2020-02-16 (3.20.2) Yes[13] Yes Yes BSD, Solaris
Notepad++ (compare) Various Yes; GPLv3 Yes 2009 2015-01-06 (1.5.6.6) Yes[14] No No
Perforce P4Merge Perforce No; Proprietary Yes 2019 (2019.1/1815056) Yes Yes Yes Sun Solaris
Pretty Diff Austin Cheney[15] Yes; MIT-compatible Yes 2009 2019-09-02 (101.2.6) Yes (Web) Yes (Web) Yes (Web) Node.js
Tkdiff Tkdiff[16] Yes; GPLv2+ Yes 2003 (or before) 2021-03-24 (v5.2.1) Yes (Tcl) Yes (Tcl) Yes (Tcl) Anything with Tcl
Total Commander (compare) Christian Ghisler[17] No; Proprietary No 2020-03-25 (v9.51) Yes No No
twdiff (TextWrangler Diff Helper)[data missing] Bare Bones Software, Inc.[18] No; Proprietary Yes; with TextWrangler 2012 (1.0 (v22)) No Yes No No
vimdiff Bram Moolenaar et al. Yes; GPL-compatible[19] Yes 2001 2016-10-03 (v8.0.0022) Yes Yes Yes Anything with vim
WinDiff Microsoft[20] No; Proprietary Yes; Part of Platform SDK 1992 2010-05-14 (v6.1.7716.0) Yes No No No
WinMerge Dean Grimm[21] Yes; GPL Yes 1998 2022-01-27 (v2.16.18) Yes (Win95 and up) Yes (in wine[22]) Yes (in wine[22]) 2 GB
KDiff3[data missing] (part of KDE SDK,[23] as well as a plug-in to KDE Dolphin file manager)[24][25] Joachim Eibl and KDE SDK KDiff3 Team[26] Yes GPL v2 Yes <2004 (v0.9.86) 2023-01-13 (v1.10) Yes as part of KDevelop KDE SDK download site or from Windows store or KDE download site (most recent version) as separate application. Yes Can be downloaded from KDE SDK download site or as separate stand-alone application from KDE download site Yes Install from your Linux distribution repositories, or as AppStream, from [1], or as GIT project KDE Gitlab[27] or from/on [2].[28] Any other Unix with KDE/KF5, Qt5 and CMake, e.g. FreeBSD[29] & NetBSD[30] ?
Name Creator FOSS Free First public release date Year of latest stable version Windows Macintosh Linux Other platforms Max supported file size

Compare features edit

Name Show in-line changes Directory comparison Binary comparison Moved lines 3-way comparison Merge Structured comparison[b] Manual compare alignment Image compare
Beyond Compare Yes Yes Yes Yes Yes (Files and Folders) Yes (Pro only) Yes Yes
Compare++ Yes Yes Yes Yes Yes (C/C++,C#,Java,Javascript,CSS3)
diff No Yes partly No No No
diff3 No No Yes (non-optional)
Eclipse (compare) Yes No (only ancestor) Yes No
Ediff Yes Yes Yes Yes Yes
ExamDiff Pro Yes Yes Yes Yes[31] Yes (ExamDiff Pro Master only)[32] Yes manual synchronization
Far Manager (compare) Yes (Via plugin)[33] Yes Yes Yes (Via plugin)[33] No No
fc No No Yes No No
FileMerge (aka opendiff) Yes Yes Yes Yes (optional ancestor) Yes
Guiffy SureMerge Yes Yes Yes Yes Yes Yes Yes
IntelliJ IDEA (compare) Yes Yes Yes No Yes Yes Yes Yes
jEdit JDiff plugin Yes No Yes
Lazarus Diff
Meld Yes Yes No No Yes Yes line alignment, unlink scroll
Notepad++ (compare) Yes No No Yes No No No
Perforce P4Merge Yes No No Yes Yes Yes
Pretty Diff Yes Yes No No No No Yes No
Tkdiff Yes No No No No No
Total Commander (compare) Yes Yes Yes No No Yes No resync comparison No
vimdiff Yes Yes (via DirDiff plugin) Yes Yes
WinDiff Yes Yes Yes Yes No No
WinMerge Yes Yes Yes Yes (via Options) Yes Yes Yes Yes
Name Show in-line changes Directory comparison Binary comparison Moved lines 3-way comparison Merge Structured comparison[b] Manual compare alignment Image compare

API / editor features edit

Name GUI CLI Scripting Horizontal / vertical Syntax highlighting Reports
Beyond Compare Yes Yes Yes Both Yes XML, HTML, CSV, Text, Unix Patch
Compare++ Yes Yes Both Yes HTML, Text(combined or side-by-side)
diff No Yes Horizontal Yes pipe to diff-highlight[34]
diff3 No Yes Horizontal
Eclipse (compare) Yes Vertical Yes
Ediff Yes Yes elisp Both Yes
ExamDiff Pro Yes Yes optional Yes UNIX, HTML, Diff
Far Manager (compare) Yes Yes Yes Yes No
fc No Yes Horizontal
FileMerge (aka opendiff) Yes Yes Vertical Yes No
Guiffy SureMerge Yes Yes Java API Both Yes HTML, Text, Unix Patch
IntelliJ IDEA (compare) Yes Yes Vertical Yes
jEdit JDiff plugin Yes Both Yes
Lazarus Diff Yes Yes
Meld Yes No Yes No
Notepad++ (compare) Yes Yes Both Yes No
Perforce P4Merge Yes Yes Vertical Yes No
Pretty Diff Yes Yes JavaScript Both Yes XHTML
Tkdiff Yes
Total Commander (compare) Yes Both No No
vimdiff Yes Yes vim script Both Yes HTML
WinDiff Yes Yes Horizontal No Text
WinMerge Yes Yes Both Yes CSV, Tab-delimited, HTML, XML
Name GUI CLI Scripting Horizontal / vertical Syntax highlighting Reports

Other features edit

Some other features which did not fit in previous table

Name ZIP support FTP support SFTP support Version control browsing Patch creation Patch application Patch preview Unicode support XML-aware
Beyond Compare Yes Yes Yes SVN Yes Yes Yes Yes
Compare++ SVN, CVS, Git, Microsoft TFS, Perforce, VSS using command line Yes
diff No No No Yes Yes with patch Yes with patch No No
diff3 No No No
Eclipse (compare) Yes CVS, Subversion, Git, Mercurial, Baazar Yes
Ediff Yes Yes RCS, CVS, SVN, Mercurial, git (anything supported by Emacs' VC-mode)[35] Yes Yes Yes
ExamDiff Pro Yes[36] Yes[37] normal diff only Yes
Far Manager (compare) No No No No No No Yes No
fc No No No
FileMerge (aka opendiff) No supported by OS No No No
Guiffy SureMerge Yes Yes Yes Yes Yes[c]
IntelliJ IDEA (compare) Yes Yes Yes Yes Yes Yes Yes Yes
jEdit JDiff plugin Yes Yes Yes Yes Yes Yes Yes
Lazarus Diff
Meld CVS, Subversion, Git, Mercurial, Baazar Yes Yes
Notepad++ (compare) No Yes[38] Git, Subversion (compare against base) No No No Yes No
Perforce P4Merge No Yes
Pretty Diff No No No No No No No Yes Yes
Tkdiff No No CVS, RCS, Subversion No No No No No
Total Commander (compare) Yes Yes Yes No No No No Yes No
vimdiff Yes Yes Yes Yes
WinDiff No No No No
WinMerge Yes No Mercurial,[39] Subversion,[40] Visual Source Safe, Rational ClearCase[41] Yes Yes
Name ZIP support FTP support SFTP support Version control browsing Patch creation Patch application Patch preview Unicode support XML-aware

Aspects edit

What aspects can be / are compared?

Name Filename casing CRC Filedate Daylight saving Character casing
Beyond Compare Yes Yes Yes Yes Yes
Compare++ Yes Yes Yes Yes
diff Yes No No No Optional
diff3
Eclipse (compare)
Ediff
ExamDiff Pro No Yes Yes Yes Yes
Far Manager (compare) Yes No Yes No Yes
fc No Optional
FileMerge (aka opendiff) No No No Optional
Guiffy SureMerge filesystem dependent Yes Yes
IntelliJ IDEA (compare)
jEdit JDiff plugin
Lazarus Diff
Meld
Notepad++ (compare) No No No Yes
Perforce P4Merge No No No Yes
Pretty Diff No No No Optional
Tkdiff
Total Commander (compare) Optional Yes (in synchronize only) Optional
vimdiff No No No No Yes
WinDiff No No when different Yes Optional
WinMerge No No Optional Optional
Name Filename casing CRC Filedate Daylight saving Character casing

Time zone effects edit

When files are transferred across time zones and between Microsoft FAT and NTFS file systems, 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 (DST). Some, but not all, file comparison and synchronisation software can be configured to ignore the DST and time-zone differences.[d] Software known to have daylight-saving compensation is marked in the Aspects table.

See also edit

Notes edit

  1. ^ Ediff requires a diff utility to function. As of December 2017, diff is not bundled with Emacs or Windows, so use of Ediff in a Windows environment requires installation of both Emacs and a diff implementation like GNU diff.
  2. ^ a b Compare logical sections (class, methods).
  3. ^ UTF8, UTF16, MBCS, SJIS, over 150 file encoding and character set formats.
  4. ^ Example: "Beyond Compare" help describes a user setting "timezone differences – ignores timestamp differences that are multiples of an exact hour."

References edit

  1. ^ Scooter Software
  2. ^ "Coode Software". Archived from the original on 2018-12-21. Retrieved 2020-12-13.
  3. ^ Compare++ Operating system information
  4. ^ Michael Kifer
  5. ^ PrestoSoft
  6. ^ "Far2l". GitHub. 26 July 2022.
  7. ^ Microsoft
  8. ^ NeXT Product Marketing (Fall 1993). "What's New in Release 3.2?". NEXTSTEP in Focus. NeXT Computer, Inc. 3 (4). Retrieved 18 July 2014.
  9. ^ Guiffy Software
  10. ^ JetBrains
  11. ^ jedit.org
  12. ^ Stephen Kennedy
  13. ^ Meld/Windows
  14. ^ Notepad++ compare plugin
  15. ^ Pretty Diff
  16. ^ tkdiff
  17. ^ Christian Ghisler
  18. ^ Bare Bones Software, Inc.
  19. ^ vim license
  20. ^ Microsoft
  21. ^ Dean Grimm
  22. ^ a b WinMerge in Wine
  23. ^ "KDE SDK Project Page". KDE Invent: KDE SDK. Retrieved 2023-03-09.
  24. ^ "KDiff3". KDE Applications. Retrieved 2023-03-09.
  25. ^ "The KDiff3 Handbook". docs.kde.org. Retrieved 2023-03-09.
  26. ^ "KDE KDiff3". Retrieved 2023-03-09.
  27. ^ "KDevelop / KDevelop · GitLab (full KDevelop project)". GitLab. Retrieved 2023-03-09.
  28. ^ "Using KDiff3 as a Git Diff and Merging Tool". docs.kde.org. Retrieved 2023-03-09.
  29. ^ "FreeBSD/Setup/Ports - KDE Community Wiki". community.kde.org. Retrieved 2023-03-09.
  30. ^ "pkgsrc.se | The NetBSD package collection". pkgsrc.se. Retrieved 2023-03-09.
  31. ^ Examdiff
  32. ^ Examdiff
  33. ^ a b Visual Compare
  34. ^ "Git/Contrib/Diff-highlight at master · git/Git". GitHub.
  35. ^ gnu.org Support-for-Version-Control
  36. ^ through a plug-in
  37. ^ through a plug-in
  38. ^ Notepad++ FTP plugin
  39. ^ "tortoisehg / stable / wiki / FAQ —". Bitbucket.org. Archived from the original on 2010-07-15. Retrieved 2010-07-06.
  40. ^ "Using WinMerge with other tools – WinMerge 2.12 Manual". Winmerge.org. Archived from the original on 2010-07-10. Retrieved 2010-07-06.
  41. ^ "About". WinMerge. Archived from the original on 2010-07-03. Retrieved 2010-07-06.