How do I show tracked changes in the compiled PDF?

Use the changes package: \added{text}, \deleted{text}, and \replaced{new}{old} mark edits in color in the PDF, and \listofchanges prints a summary. For comparing two full versions, latexdiff is the standard tool — run latexdiff old.tex new.tex > diff.tex and compile diff.tex to get a marked-up PDF with additions underlined and deletions struck through. Many journals accept a latexdiff PDF as the revision document for a resubmission.

Can I leave comments in LaTeX without them appearing in the PDF?

Yes. The simplest way is a % comment, which LaTeX ignores entirely. For visible margin notes during drafting, the todonotes package gives \todo{fix this} bubbles you remove before submission. In a collaborative editor, inline comments are attached to the text and stored separately from the source, so they never compile into the PDF — the cleanest option for co-author discussion.

What is the best way to handle reviewer comments on a resubmission?

Generate a latexdiff PDF so reviewers see exactly what changed, and write a point-by-point response letter mapping each reviewer comment to your edit. Keep the previous submitted version tagged (in Git or your editor's history) so latexdiff has a clean baseline. This combination — a visual diff plus a structured response — is what most journals expect and speeds up the second review round.

Track Changes & Comments in Collaborative LaTeX

Collaborative LaTeX tools let co-authors comment and track changes inline — like Google Docs for papers — using the changes package, latexdiff, or an editor's live comments. You can mark additions and deletions in the compiled PDF, generate a marked-up diff between versions, or discuss edits without touching the source. Here are the three approaches and when to use each.

1. Inline tracked changes with the changes package

\usepackage{changes}
...
The result was \replaced{0.94}{0.81} after tuning.
We \added{also} tested the baseline.
This sentence is \deleted{no longer needed}.
\listofchanges

Each edit shows in color in the PDF, with an optional author label. This is best for marking specific edits you want a co-author to see.

2. Version diffs with latexdiff

To show everything that changed between two drafts:

latexdiff old.tex new.tex > diff.tex
# then compile diff.tex

The output PDF underlines additions and strikes through deletions. Most journals accept a latexdiff PDF as the revision document — pair it with a point-by-point response letter.

3. Comments that never compile

| Method | Visible in PDF? | Use for | |---|---|---| | % comment | No | Private notes in source | | \todo{...} (todonotes) | Yes, margin bubble | Drafting reminders | | Editor inline comment | No (stored separately) | Co-author discussion |

A plain % comment is invisible; todonotes shows margin bubbles you strip before submission.

4. Live comments in a collaborative editor

In a real-time editor, comments attach to a text selection and live outside the source, so they never compile into the PDF and every co-author sees them in context. This is the cleanest review workflow — the real-time collaboration model applied to feedback, and the backbone of the supervisor–student workflow.

5. A clean revision workflow

Tag the submitted version (Git or editor history).
Make edits on a new version.
Run latexdiff against the tagged baseline.
Compile the diff; write a response letter.
Submit the diff PDF plus responses.

→ Comment and review in real time — no emailed PDFs — in LetX. Comparing tools? See LetX vs Overleaf.

Written by Shihab Shahriar Antor — AI Engineer & Founder of Shahriar Labs, maker of LetX.