Paste original and modified text.
Hit Compare to see a line-by-line breakdown. Tweak advanced options to ignore case or whitespace.
Two boxes. One click.
No setup, no account — here's the entire flow.
Paste the original
Drop the original version of your text, code, or document into the left box.
Paste the modified
Put the changed version into the right box. You can also hit "Load sample" to try it first.
Set your options
Toggle "Ignore case" or "Ignore whitespace" if you only care about meaningful content changes.
Compare & review
Click Compare. Added lines glow teal, removed lines glow amber, and unchanged lines stay muted.
Clear, line-by-line insight.
Everything you need to spot exactly what changed between two versions.
Line-level diff
Each line is compared individually so you can see exactly what was added, deleted, or kept.
Flexible matching
Filter out formatting noise and focus on meaningful content changes with a single toggle.
Line numbers
Keep your bearings in long documents with optional line numbers next to every row.
Questions people actually ask.
The short answers — with the long ones one tap away.
How does the text diff checker work?+
Paste the original text in the left box and the modified text in the right box. The tool compares them line by line and highlights lines that were added, removed, or stayed the same.
Can I ignore case or whitespace differences?+
Yes. Open the Advanced options panel and toggle "Ignore case" or "Ignore whitespace" to focus on meaningful content changes instead of formatting noise.
Is there a limit to how much text I can compare?+
No hard limit — the tool runs entirely in your browser, so very large documents may take a moment longer to process on older devices.
Is my text stored or sent anywhere?+
No. Everything is compared locally in your browser. Your text is never uploaded, logged, or stored by StudyWithSTEM.
Does it work for code?+
Yes. The diff checker works for any plain text, including source code. It compares line by line, which is exactly how most code diff tools work.