Paste two versions of a text, code block, or document to instantly see what changed. Generates a shareable link so colleagues see the exact same diff.
Original text
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Modified text
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What is a diff checker?
A diff checker (short for difference checker) compares two versions of a text or code file and highlights what was added, removed, or unchanged. The output format — green for insertions, red for deletions — mirrors the style used in GitHub pull requests and Git's git diff command.
Compare files from the command line
# Unix diff (side-by-side)
diff -y file_v1.txt file_v2.txt
# Git diff between two commits
git diff abc1234 def5678 -- path/to/file.py
# Python: compute diff programmatically
import difflib
with open('v1.txt') as f: lines_a = f.readlines()
with open('v2.txt') as f: lines_b = f.readlines()
diff = list(difflib.unified_diff(lines_a, lines_b, fromfile='v1.txt', tofile='v2.txt'))
print(''.join(diff))