What Is an SFV File?

How to Open, Edit, and Convert SFV Files

Screenshot of SFV files in Windows 10 that are opened with Notepad
SFV Files.

 Lifewire

A Simple File Verification file is used to verify data. A CRC32 checksum value is stored in a file that usually, though not always, has the .SFV file extension appended to it.

A program that can calculate the checksum of a file, folder, or disk, is used to produce the SFV file. The purpose is to verify that a particular piece of data is truly the data you expect it to be.

The checksum changes with each and every character that's added or removed from a file, and the same applies to files and file names within folders or disks. This means that the checksum is unique for every single piece of data, even if one character is off, the size is slightly different, etc.

For example, when verifying the files on a disc after they've been burned from a computer, the program doing the verifying can check that all the files that were supposed to be burned, were actually copied to the CD.

The same is true if calculating the checksum against a file you've downloaded from the internet. If the checksum is calculated and shown on the website, and you check it again after it's downloaded, a match can assure you that the same file you requested is the one you now have, and that it wasn't corrupted or purposefully modified in the download process.

Note: SFV files might sometimes be referred to as Simple File Validator files.

How to Run a Simple File Verification (Make an SFV File)

MooSFV, SFV Checker, and RapidCRC are three free tools that can generate the checksum of a file or group of files, and then place it into an SFV file. With RapidCRC, you can create an SFV file (and even an MD5 file) for every single file in your list or every directory, or even make just one SFV file for all the files.

Another is TeraCopy, a program used to copy files. It can also verify that they were all copied and none of the data was dropped along the way. It supports not only the CRC32 hash function but also MD5, SHA-1, SHA-256, Whirlpool, Panama, RipeMD, and others.

Create an SFV file on macOS with SuperSFV, MacSFV, or checkSum+; or use Check SFV if you're on Linux.

QuickSFV is another that works on Windows and Linux, but it's run entirely through the command line. For example, in Windows, with Command Prompt, you have to enter the following command to produce the SFV file:

quicksfv.exe -c test.sfv file.txt

In this example, "-c" makes the SFV file, identifies the checksum value of "file.txt," and then places it into "test.sfv." These commands assume that the QuickSFV program and file.txt file are in the same folder.

How to Open an SFV File

SFV files are plain text, which means they can be viewed with any text editor like Notepad in Windows, Leafpad for Linux, and Geany for macOS. Notepad++ is another popular text editor and SFV opener for Windows.

Some of the programs from above that calculate the checksum, can also be used to open SFV files (TeraCopy is one example). However, instead of letting you view the plain text information held within it like a text editor does, they normally will open the SFV file or file in question, and then compare a new checksum test against the one you have.

SFV files are always created like this: the file name is listed on one line followed by a space, which is then followed by the checksum. Additional lines can be created below others for a list of checksums, and comments can be added using semicolons.

Here's one example of an SFV file created by RapidCRC:

; Generated by WIN-SFV32 v1 (compatible; RapidCRC http://rapidcrc.sourceforge.net )
;
uninstall.exe C31F39B6

How to Convert SFV Files

An SFV file is just a plain text file, which means you can only convert them to other text-based file formats. This might include TXT, RTF, or HTML/HTM, but they usually remain with their SFV file extension because the purpose is just to store the checksum.

Since these files are in a plain text format, you can not save your SFV file to a video file format like MP4 or AVI, or any other kind like ISO, ZIP, RAR, etc.

Still Can't Open the File?

It's unlikely that a regular text editor will automatically recognize SFV files. If this is the case, and nothing happens when you double-click to open it, try opening the program first and then using the Open menu to display the SFV file.

Tip: If you do want your text editor to recognize and automatically open SFV files in Windows, you can change the file associations in Windows.

Some file extensions might look an awful lot like SFV files but are in fact not related to them at all. This is the case with ones like SFM and SVF (a vector file format), both of which can easily be confused with SFV, but neither of which work with the programs listed above.

Also, remember that SFV files are sometimes stored along with video files so that you can be sure that the entirety of the video is intact. In this bunch there is often an SRT file used for subtitles. While the two file formats are text-based and might look similar in name, they are not related and can not be converted to or from each other for any useful purpose.