Core legal skills
How to run compares / redlines and mark up documents
How to generate and read document compares and redlines, so you can see exactly what changed and learn from your supervisor's amendments.
The short version
A redline (or compare) shows exactly what changed between two versions of a document — text added, deleted or moved. In Word, generate one with Review → Compare, always setting the earlier version as 'Original' and the newer as 'Revised'; mark up your own edits with Track Changes (Ctrl+Shift+E) using conventional colours; and always review once in 'No Markup' view before you send.
As a junior lawyer, I was expected to know how to run compares and mark up documents from day one. Nobody gave me a formal training session — so naturally, I made mistakes. Here's what I wish someone had shown me earlier.
What is a redline?
A redline shows the differences between two versions of a document — what's been added, deleted, or moved. You'll use them constantly: when the other side returns a draft, when you're showing your supervisor what you've changed, or when you're sending marked-up amendments to a client.
How to run a compare in Word
Open the Compare function — Review tab → Compare → "Compare two versions of a document (legal blackline)".
Choose the right files — Original = the earlier version, Revised = the newer version. Getting these backwards is one of the most common mistakes.
Adjust your settings — click "More >>", tick "Ignore formatting", set changes at word level, and choose where to show changes (a new document is cleanest).
Save and name clearly — e.g. "COMPARE – EPC Contract – Version 2 (2025.10.08) v Version 1 (2025.10.01)".
Review before sending — check the compare is legible and isn't showing unnecessary formatting noise.
How to mark up a contract
Turn on Track Changes:
Review → Tracking → Track Changes (shortcut: Ctrl+Shift+E).
Set your colours to best practice: additions = blue / underline, deletions = red / strikeout, moved text = green.
Keep markup to a minimum — don't rewrite whole clauses if only a few words change.
Use comment bubbles to explain your changes. Tag them with your initials and the date:
JF Note 08.10.25 — Confirm if 30 or 60 days' notice.
Common mistakes to avoid
Comparing wrong versions — label originals and revised files clearly before you start.
Doubled-up comment bubbles — delete comments from the original before comparing.
Too many formatting changes — tick "Ignore formatting" before running.
Wrong view when sending — confirm you're in "All Markup" before sending.
Broken cross references — select all + F9 to update, then search "Error!" to spot issues.
Never reviewed clean — always check once in "No Markup" view before sending.
Frequently asked questions
How do I compare two versions of a document in Word?
Go to Review → Compare → 'Compare two versions of a document (legal blackline)', set the earlier version as Original and the newer one as Revised (getting these backwards is the most common mistake), tick 'Ignore formatting', and output the result to a new document.
What's the difference between a redline and track changes?
A redline (compare) is generated after the fact to show the differences between two saved versions; Track Changes records your edits live as you make them. You'll use a compare to see what the other side changed, and Track Changes to show your own mark-up.
What are the most common mistakes when running a compare?
Comparing the wrong versions, leaving old comment bubbles in so they double up, too many formatting changes (tick 'Ignore formatting'), sending in the wrong view (confirm 'All Markup'), and never checking the document once in 'No Markup' before it goes out.
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