Blackline vs Redline: Choose the Right Contract File

A redline usually shows proposed edits; a blackline usually compares two saved versions. The labels overlap, and a comparison can itself contain tracked changes. Name the two input files and the decision you need to make: a comparison against the wrong baseline can accurately show differences while answering the wrong question.

Choose the deliverable by the reviewer’s task

Specify what the recipient should decide rather than relying on the file’s label. An editable negotiation draft, a comparison report and a signature candidate serve different purposes. They can all be useful on the same agreement. A clean appearance does not establish approval, and a file containing markup does not necessarily preserve the whole negotiation history.

Color and job title do not define the file

A blackline is not necessarily a black-and-white PDF, and a redline is not limited to a lawyer’s edits. Inspect the production method, format and permissions. For example, if a colleague asks for the blackline, respond with a precise confirmation: compare the supplier’s October 10 return with the October 8 draft we sent, and include comments and formatting if those are in scope.

Understand what each method actually records

In a tracked working draft, proposed insertions and deletions can be accepted or rejected. If tracking was disabled, a silent edit may not appear as a proposal. If earlier changes were accepted, the current markup may no longer show them. Preserve exchanged versions rather than treating one active file as a complete record of every negotiation turn.

For Word for Microsoft 365 and desktop Word for Windows, Microsoft calls its two-file comparison a legal blackline. Its instructions allow comparisons of comments, formatting and text. The result can show changes as tracked changes. That contradicts a blanket rule that blacklines cannot contain deletions, comments or tracking. A tool’s settings determine what is included.

A comparison answers what differs between selected inputs. It cannot establish the business reason, authority or approval behind a difference. Read the entire changed clause in context and route the decision to the responsible reviewer. Do not call a difference intentional concealment merely because it was untracked.

Select the baseline for the decision in front of you

Write the comparison question before selecting files. Keep the original received attachment or saved repository version, and identify any missing approval evidence.

These questions require separate comparisons. A concession from the template may already be approved, while a small new payment edit may still require authorization. Include the referenced schedules, order forms and exhibits in the scope. A matching main agreement does not settle a change in a separate attachment. See our [order-form conflict guide](/blog/order-form-master-agreement-conflict).

A correct comparison can still miss the approval question

A reviewer who sees only A against B never examines C’s payment period. The comparison is accurate for its inputs but cannot answer whether C matches B. Comparing two copies of C also cannot establish that C matches the approval.

Hold the payment difference for a decision. Ask whether it was intended and authorized. If corrected, compare the corrected candidate with B again. If approved, record the decision and the exact resulting file. Keep the originally received C so your record distinguishes the incoming proposal from the approved release.

Synthetic versions, sample wording to check against the actual agreement

A, service-template.txt: Annual fee USD 24,000. Invoices payable within 30 days.
B, service-approved.txt: Annual fee USD 20,000. Invoices payable within 30 days.
C, service-signature-candidate.txt: Annual fee USD 20,000. Invoices payable within 15 days.

Generate the comparison without overwriting your evidence

The Microsoft instructions cover Word for Microsoft 365 and other desktop versions of Word for Windows. The steps, comparison options and tracked-change prompt below are scoped to those Windows desktop versions. On Word for Mac or the web, the menu path may differ; check platform-specific instructions rather than assuming these controls behave the same way.

For those Windows desktop versions, Microsoft describes a prompt when either input contains tracked changes. In the generated third document, original-document tracked changes are accepted and revised-document changes appear as tracking. That comparison view is not an untouched historical negotiation record. Keep the original files and record how the prompt was handled.

If the known difference is absent, stop and inspect the selected files and options. Do not send a comparison merely because the software generated an output successfully. Review complete clauses, definitions, tables, cross-references and attachments in scope.

1. Open the two files. On Review, choose Compare, then Compare two versions of a document, the legal blackline option.
2. Select Original and Revised deliberately. Record why the Original answers your question.
3. Choose comparison options, including comments, formatting and text, and whether the display is at word or character level.
4. Keep the new-document output. Read any prompt about existing tracked changes before continuing.
5. Inspect the generated result and check a known difference against both inputs. In the synthetic example, confirm the 30-to-15-day payment change.
6. Save the comparison with its input names, settings and scope. Use Combine rather than this comparison option when the task is merging multiple reviewers’ revisions.

Send a short comparison record with the files

Completed synthetic record: Original is service-approved.txt, Revised is service-signature-candidate.txt. Method is manual comparison of one clause only; no formatting or attachments were examined. Difference is payment from thirty to fifteen days, with the USD 20,000 fee unchanged. Status is unresolved, and Finance owns authorization of the payment change.

A cover note can say: Attached is C compared with B, the version covered by the identified approval record. The payment-period difference remains open. This copy is for review, not signature. Replace those shorthand labels with actual file identifiers.

Copyable comparison handoff

Decision supported: [question]
Original file/version: [exact identifier]
Why this baseline: [approval or exchanged draft reference]
Revised file/version: [exact identifier]
Tool/version and options: [details]
Existing tracked changes handled: [details]
Scope and missing attachments: [details]
Known difference checked: [entry]
Open decisions/owner: [entry]
Status: proposed, review-only or approved for signature
Approval reference and exact outgoing file: [entry]

Keep comparison, approval and release copies separate

You may need an editable negotiation copy, a reference comparison and a proposed execution copy. Label each role. Preserve the marked record before preparing a separate release file. Acceptance of tracked edits must follow the substantive decisions, not replace them.

Microsoft’s Track Changes instructions explain that hiding changes does not remove them; use Accept or Reject to remove markup. Its acceptance instructions explain that earlier insertions and deletions can remain marked even when tracking is off, and that accepting or rejecting removes those markings. Verify the intended final wording rather than relying on a default view.

Inspect the external copy for internal notes. Microsoft says resolved threads remain and @mentions do not restrict audience. Run Document Inspector on a copy because removal may not be reversible. During active negotiation, indiscriminate cleanup can remove proposals the recipient still needs.

Use our [redlining guide](/blog/how-to-redline-a-contract) for the full sequence. If a tool changes the route between Word and a platform, run the [two-round software trial](/blog/contract-redlining-software-word-round-trip) on synthetic files before relying on it.

Frequently asked questions

What does blackline mean on a document?

It commonly means differences between two named saved versions. Ask which files were compared, which settings were used and what decision the report supports.

What is a redline in legal terms?

It usually means proposed additions, deletions or revisions made visible for review. Markup alone does not establish approval.

Are blackline and redline interchangeable?

Terminology overlaps. Agree on the actual deliverable: editable proposals, a comparison against a named baseline or a signature candidate.

Does accepting all changes create a blackline?

Acceptance settles the pending edit state in that file. It does not compare that file with a separate approved version. Keep the approved baseline and run the appropriate comparison.

Can a blackline show comments or deletions?

Yes, depending on the method and settings. Microsoft’s legal-blackline instructions for Word for Microsoft 365 and desktop Word for Windows explicitly include comment comparison options and output shown as tracked changes.

Which baseline should I use before signature?

The exact approved text, with the intended attachment scope. Use a separate template comparison if you also need overall deviations from policy.

Why is it called a redline?

The name is associated with marked edits, but color is not a reliable technical distinction. This guide relies on documented modern controls rather than an unverified historical origin story.

Does a comparison prove approval?

No. Preserve the approval owner, decision and exact covered file separately. Resolve unexplained differences and missing attachment evidence before release.

Sources

• Word Track Changes
• Word accept changes
• Word legal blackline
• Word comments
• Document Inspector

Related: Redline a contract step by step · Test software file exchanges · Check conflicting attachments