How to Compare Two Texts & Find Differences Online — Step by Step

Someone says they "didn't change anything" in the document they sent back. You need proof. A text diff tool shows every single difference between two texts — every added word, every deleted sentence, every changed number. Here is exactly how to use one.

Step 1: Copy Your Original Text

Grab the original version from wherever it lives:

• Email draft — copy the first version you wrote
• Contract — copy the original terms you agreed to
• Code file — copy the version before changes
• Blog post — copy the draft before editing
• API response — copy the expected JSON output
• Terms of Service — copy the version you originally accepted

Step 2: Paste Both Versions

Open Text Diff and paste your texts:

1. Paste the original text in the left panel
2. Paste the modified text in the right panel
3. Click compare

The tool instantly processes both texts and highlights every difference with color coding.

Step 3: Read the Diff Results

What You See	What It Means	Action
Green highlighted text	This text was added in the modified version	Review — was this addition intentional?
Red highlighted text	This text was removed from the original	Review — should this have been deleted?
No highlighting	Text is identical in both versions	No action needed
Many green sections	Significant additions were made	Read each addition carefully
Many red sections	Significant content was removed	Verify nothing important was cut

Real Scenario: Comparing Email Drafts

You wrote a sales email, then revised it. Before sending, you want to make sure you didn't accidentally delete the pricing paragraph:

1. Copy version 1 of the email (from your drafts or sent folder)
2. Paste it on the left side of Text Diff
3. Copy version 2 (your current draft)
4. Paste it on the right side
5. Scan for red highlights — nothing critical was removed. Green shows your new closing paragraph. Send with confidence.

Real Scenario: Verifying Copy Edits

Your editor returns a "lightly edited" article. Paste the original and edited versions to see exactly what changed:

• Did they fix typos? (Good — accept those)
• Did they rewrite your opening paragraph? (Check if the new version matches your intent)
• Did they remove a section? (Was it intentional or an accident?)
• Did they change any factual claims? (Verify accuracy before publishing)

Real Scenario: Comparing API Responses

Your test suite expects a specific JSON response. The API is returning something different. Paste both into the diff tool:

• A field name changed from user_name to username
• A nested object gained a new metadata field
• A timestamp format changed from ISO to Unix

The diff highlights the exact fields that differ — faster than scanning two JSON blocks line by line.

Real Scenario: Terms of Service Changes

A service you use updated their Terms of Service. Copy the archived version (Wayback Machine or your saved copy) and compare it against the new version. Common changes to watch for:

• Data usage policies expanding
• Arbitration clauses being added
• Refund or cancellation terms changing

Pair With These Tools

• Text Diff — compare two text versions
• Find & Replace — make batch changes after finding differences
• Word Counter — check if edits changed your word count significantly
• Diff Checker — code-focused comparison with syntax support
• JSON Formatter — format JSON before comparing API responses