Practical Guides

How to Verify File Integrity.

A step-by-step CLI and GUI tutorial for verifying SHA-256 checksums of downloaded software on Ubuntu, macOS Terminal, and Windows PowerShell.

Category: Practical GuidesReading Time: 5 min readPublished: 2026-08-20

1. Verifying on Linux (Ubuntu, Debian, Fedora)

Use the standard `sha256sum` utility built into GNU coreutils:

BASHSyntax Example

# Single file check:
sha256sum ubuntu-24.04-desktop-amd64.iso

# Automated batch verification against published SHA256SUMS file:
sha256sum -c SHA256SUMS 2>&1 | grep OK

2. Verifying on macOS (Terminal)

Use the built-in `shasum` command with the `-a 256` flag:

BASHSyntax Example

shasum -a 256 /path/to/downloaded-installer.dmg

3. Verifying on Windows (PowerShell)

Open PowerShell and execute `Get-FileHash`:

POWERSHELLSyntax Example

Get-FileHash -Algorithm SHA256 .\software-installer.exe

4. What to Do If Checksums Do Not Match

If the computed checksum differs by even a single character from the vendor’s published hash: 1. Do NOT execute or open the file. 2. Delete the file immediately. 3. Re-download from an authentic official mirror over HTTPS.

Frequently Asked Questions.

Frequently Asked Questions

Clear answers to common cryptographic and implementation questions.

What causes checksum mismatches?

Interrupted downloads, corrupted disk storage, proxy tampering, or man-in-the-middle malware injection.

← Previous GuideHow File Hashing Works: Chunked Streams, Buffer Slices, and Memory Next Guide →Is MD5 Secure? Cryptanalysis History and Collision Vulnerabilities

How to Verify File Integrity.

1. Verifying on Linux (Ubuntu, Debian, Fedora)

2. Verifying on macOS (Terminal)

3. Verifying on Windows (PowerShell)

4. What to Do If Checksums Do Not Match

Frequently Asked Questions.

Frequently Asked Questions

Recommended Tools for this Topic

File Hash Generator

Hash Comparator

File Integrity Checker