Guides
Practical guides to file comparison, diff tools, and document workflows — written for developers, legal teams, writers, and analysts.
How to Compare Two PDF Files Online
A step-by-step guide to comparing PDF documents in your browser — no software installation, no Microsoft Word required.
git diff vs. an Online Diff Tool: When to Use Which
Both git diff and browser-based diff tools highlight code changes — but they serve different purposes. Here is how to choose.
Diff Algorithms Explained: Myers, Patience, and Histogram
What actually happens when a diff tool compares two files? A plain-English guide to the three most common diff algorithms and when each one produces better results.
How to Track Changes in Word Documents Without Microsoft Word
You do not need Microsoft Word to see what changed between two document versions. Here are the fastest ways to compare Word files and PDFs online.
How to Compare Two Images Online: A Visual QA Guide
A practical guide to pixel-level image comparison — what the different viewing modes mean, when to use each one, and common workflows for designers, developers, and QA teams.
How to Compare Two ZIP Archives and Folder Structures Online
A guide to comparing the contents of two ZIP files or folder snapshots — understanding which files were added, removed, or changed, and seeing the line-level diffs inside each file.
How to Compare Two Excel Files: VLOOKUP vs. a Diff Tool
VLOOKUP can find matching values but it cannot tell you what changed. Here is how a dedicated diff tool compares to Excel's built-in options for spotting differences between two spreadsheets.
How to Compare Two JSON Files Online
JSON looks simple until two files that should match refuse to. Here is how to find the exact difference between two JSON files — and why key order and formatting trip people up.
How to Compare Two CSV Files and Find Changed Rows
Two exports of the same data, and you need to know which rows were added, removed, or edited. Here is a reliable way to compare CSV files without writing a script.
How to Compare Two Lists and Find What Is Different
Two lists of names, emails, IDs, or SKUs — and you need to know what is in one but not the other. Here is the fastest way to find the difference between two lists.
How to Compare Two XML Files and Find What Changed
XML configs, feeds, and exports are verbose and easy to break with a single wrong tag. Here is how to compare two XML files and read the differences cleanly.
How to Review Code Changes Without Git: A Visual Diff Workflow
Not every code review happens in a pull request. Here is how to compare two versions of a file and review the changes visually when Git is not in the picture.
How to Find Missing or Duplicate Lines Between Two Text Files
A line dropped out somewhere between two versions of a file, or one got duplicated. Here is how to find exactly which lines are missing, added, or repeated.