How to Check Checksums in Windows 11: Complete and Updated Guide

Verify the checksum of a file in Windows 11 It is a more common task than many users think, especially for those who download software from the Internet, work with critical files, or seek to ensure that no transmission or manipulation errors have altered a file.

In this article you will discover how hashes or checksums can be calculated and verified in Windows 11, step by step and in several ways: from the terminal, using built-in utilities, and using free programs. In addition, you will learn Why modern algorithms are so important like SHA-256 or SHA-3 versus the older ones, and learn the best practices to maintain the security and integrity of your files.

What is a checksum or hash?

A checksum (or checksum) is a value generated from a mathematical algorithm that is applied to the data in a file. The result, known as hash, is a string of numbers and letters that uniquely represents the contents of that file. If the file is modified even by a single bit, the hash will change completely. That's why it's essential to detect any alteration, corruption or manipulation of files.

The use of checksums is present in downloads software, backup integrity checking, chain of custody in computer forensics, and network security protocols like HTTPS, SSH or VPNs.

Importance of hashes: Hashes allow you to confirm that a downloaded file has not been modified by a malicious third party or corrupted during the download process. Developers often publish the hash value of their installations on their websites so that users can verify that the downloaded file is exactly the same as the original.

Main checksum algorithms

There are different methods or hash algorithms, each with its own advantages and disadvantages. Here's a summary of the most commonly used ones, from the oldest to the safest and most modern:

• MD5: Very popular in the past, it generates 128-bit hashes. Nowadays, is considered unsafe Due to discovered vulnerabilities and collisions, its use is therefore not recommended for critical or security tasks.
• SHA-1: Produces 160-bit hashes. Although widely used for integrity checks until a few years ago, it is currently Not recommended its use due to demonstrated vulnerabilities.
• SHA-2 (including SHA-256 and SHA-512): It is the modern standard. SHA-256, for example, produces 256-bit hashes and is used by most security services, digital signatures, and cryptocurrencies, .
• SHA-3: Implements new hashing techniques with a different architecture, providing even greater security.
• Other algorithms (Blake2, Blake3, xxHash, RIPEMD, CRC32): Present in specific tools, they offer good performance for particular tasks, although in most critical scenarios it is recommended to opt for SHA-256 or SHA-3.

Practical tip: If you come across a file whose published verification hash is MD5 or SHA-1, if you have the option, Ask the software maintainer to provide you with a SHA-256 or higher hash., especially for sensitive or critical material.

What are hashes and checksums used for?

The hash functions and checksums are mainly used for:

• Verify file integrityIf you generate a hash and then copy the file to another location, you can generate the hash there and compare it. They should match if the file is intact.
• Check downloads: Avoid installing corrupt files or manipulated, comparing the downloaded hash with the officially published one.
• Computer chain of custody: In forensic analysis, they are used to demonstrate that a disk or image has not been altered.
• Passwords and authentication: Hashes allow passwords to be stored irreversibly and securely in databases.
• Cryptography and secure protocols: Integrity and authenticity in encrypted connections.

Important data: The hash it is not reversibleThe original file cannot be extracted from the hash, which provides information security.

Types of tools to verify checksums in Windows 11

In Windows 11, you can calculate and compare hashes using several options. Below are the most reliable and recommended options:

• Built-in utilities: From the line of commands (DCM) or PowerShell without installing additional software.
• Free third-party applications: Specialized in generating and comparing hashes, with a user-friendly graphical interface.
• Online tools: Websites where you can upload files to obtain their hashes, useful when you don't want to install anything and the file is not sensitive.

How to check checksums in Windows 11 using CMD or PowerShell

One of the fastest and safest ways to calculate a hash in Windows 11 is by using the command certutil, which comes standard with the operating system. This allows you to avoid third-party installations and is ideal for automating checks in scripts.

Step by step to calculate a hash with certutil:

1. Open the Symbol of the system (CMD) or PowerShellYou can search for "cmd" or "powershell" in the start menu.
2. Run the following command (replace filename by the path of your file and the algorithm by one of the supported ones: MD5, SHA1, SHA256, SHA384, SHA512):certutil -hashfile nombre_de_archivo algoritmo
3. Press Enter and the system will show you the calculated hash. Compare it to the published or expected value.

object lesson:
Suppose you have downloaded the file installer.iso and you want to verify that it matches the published SHA-256 checksum.

Run:

certutil -hashfile C:\Usuarios\TuUsuario\Descargas\instalador.iso sha256

The result will be an alphanumeric string that must exactly match the one listed on the official download website. If it matches, the file is authentic; if not, do not use it and download it again.

Top free programs to check hashes in Windows 11

If you prefer applications with a graphical interface or advanced features, there are numerous powerful free options. Let's review the most popular ones and the features that set them apart:

QuickHash

QuickHash It is an open source utility compatible with Windows, Linux and macOS. Does not require installation and supports multiple algorithms: MD5, SHA1, SHA-2 (256 and 512 bits), SHA-3, BLAKE2, xxHash, and others. It's ideal for advanced users, technicians, and those who need to compare files, entire folders, or even entire disks.

Among the functions it offers:

• Hash of text, individual files or multiple files (per folder).
• File copying with automatic hash integrity checking.
• Compare two files or two folders to quickly determine if they are identical.
• Hash of physical or logical volumes and Base64-encoded data.

It's very easy to use: just download, unzip, and open the executable file. To check a file's hash, select the algorithm and file, and the program will display the result.

Hash My Files

This software portable and lightweight It allows you to calculate block hashes of multiple files at once, supporting algorithms such as SHA (all its variants) and CRC32. It integrates into the Windows context menu to facilitate quick selection of files or folders. Ideal if you're looking for speed and comfort.

Simply drag the files onto the program window after opening it, and you'll have immediate access to the calculated hashes.

multi-hasher

multi-hasher It's also a compact program designed to generate and compare hashes in bulk across folders and subfolders. It supports CRC32, MD5, RIPEMD-160, SHA-1, SHA-256, SHA-384, and SHA-512. Its options include storing results, automating tasks, and comparing lists of hashes.

MD5 & SHA Checksum Utility

With this free software, you can generate and verify SHA-512, SHA-1, MD5, and SHA-256 hashes of one or more files, save the results as CSV, HTML, or TXT, and even use it to quickly verify the integrity of any downloaded file.

Other recommended alternatives

• HashCalc: Generates hashes for numerous algorithms, supports all file types and sizes, and is ideal for quick or automated calculations.
• MD5 Hash Check: Allows you to compare files, add the function to the context menu, and easily obtain results.
• Hasher Lite: Ultra-easy drag-and-drop operation, processing up to 100 files simultaneously in the free version.
• DeadHash: Ultra-lightweight, compatible with most modern algorithms, and designed for users looking for speed and simplicity.
• Hash generator: Ideal for quickly obtaining hashes of a specific file, although it does not allow comparing values ​​between multiple files.
• FCIV (Microsoft File Checksum Integrity Verifier): Microsoft tool for calculating and verifying hashes via CMD.
• Checksum Control: Open source, cross-platform, and easy-to-use for verifying MD5 and SHA-1 hashes.

Web tools for calculating and comparing hashes

If you don't want to install any software, you have online sites that allow you to generate a file's hash by uploading it directly to your browser:

• File checksums: Supports over 29 algorithms and requires no registration. Ideal for small, non-sensitive files.
• HTML5 File Hash Online Calculator: Allows you to calculate MD5, SHA-1, SHA-256, SHA-384 and SHA-512.
• Defuse Online Text & File Checksum Calculator: Supports files up to 5 MB, never stores data on its servers, and works with ASCII or UNICODE text.

Caution: Avoid uploading private or sensitive documents to third-party web services. Using online solutions is only recommended for files without confidential information.

Hash Comparison and Validation: Steps to Follow

Whichever tool is chosen, the procedure is always very similar:

1. Obtain the file and the hash published by the original provider (e.g., SHA-256 on the download site).
2. Generate the hash of the downloaded file using certutil, the program of your choice, or a web tool.
3. Compare both values. They must match exactly, with no room for difference. If they do not match, the file is different, potentially corrupted or tampered with.

Some utilities allow you to automatically compare two values ​​and indicate whether they match or not (MATCH or MIS-MATCH).

Advanced utilities for developers and administrators

In professional environments or custom development, Microsoft allows you to choose the checksum algorithm used to verify source and executable files, especially in Visual Studio compilations and code debugging. The option /ZH in the C++ compiler defines which hash algorithm to use to associate the checksum of each source file in the PDB files:

• /ZH:MD5: In Visual Studio 2019, used by default but currently discouraged due to being less secure.
• /ZH:SHA1: Like MD5, no longer recommended due to known vulnerabilities.
• /ZH:SHA_256: Since Visual Studio 2022, this is the default and most recommended option.

It is always recommended to use SHA-256 For new builds, by adjusting settings in project properties or the command line.