Redlineo

Self-hosted document comparison

Redlines that prove themselves.

Compare two versions of a document. Get back a redline that carries its own evidence — verified as it runs, fingerprinted, and tamper-evident. On your own server; nothing stored.

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Self-hosted · nothing stored · deterministic, not "AI-powered"

Endorsement · form BP 04 30 · redline

Policy period begins at 12:01 a.m. 12:01 A.M. Standard Time at the address shown.

Edition date 04/01/2025 04/01/2026.

✔ VERIFIED SHA-256 73cfd4e3…f4ab266e

How it works

Three steps. No trust required.

  • Step 1

    Drop two versions

    The older and the newer — Word or Excel — on the Compare page, or call the REST API.

  • Step 2

    Get a proven redline

    A report page comes with it: every change numbered and clickable, rate impact, and a ✔ Verified stamp.

  • Step 3

    Re-check it anytime

    Drop the file on the Verify page and it proves it is unaltered and yours. No database needed.

Read getting started What's in the report

One comparison, whichever form the reader needs

Three outputs.

  • .docx · tracked

    Word tracked changes

    Real Word revisions to accept or reject. The filing artifact — accept all rebuilds the revised document, reject all restores the original.

  • .docx · baked

    Baked colors

    The same changes flattened into fixed colors — insertions underlined, deletions struck through. Looks identical in every viewer; ideal for PDF.

    • insertion
    • deletion
  • .xlsx · colored copy

    Colored Excel review copy

    The real revised workbook with green/amber/red fills for reviewers who live in Excel. A review view — the Word redline remains what you file.

    • inserted
    • changed
    • deleted

Understanding the outputs →  ·  Compare Word documents, hands on →  ·  Compare Excel files, hands on →

The proof — what no other redline tool does

Three kinds of evidence, inside every file.

  • ✔Verified as it runs. The tool re-checks that accepting every change reproduces the revised document and rejecting every change restores the original — stamped on the report, in the response header, and in the UI.
  • ✔A certificate on every comparison. SHA-256 fingerprints of the exact input files, recomputable by anyone with sha256sum. No trust in us required.
  • ✔One-drop re-verification. Drop any produced file on the Verify page and it proves the file is unaltered since generation — and, with a configured secret, produced by your server.
  • ✔Evidence you can hand over. To a regulator, to opposing counsel, to a market-conduct examiner — the proof travels tamper-evident inside the file itself.

✔ VERIFIED accept-all → the revised document · reject-all → the original · X-Compare-Verified: true

Why compliance and IT say yes

Built to be checked, not trusted.

  • Self-hosted, pure Java
  • Nothing stored — computed and forgotten
  • Deterministic, not "AI-powered"
  • No Microsoft Office, no cloud
  • Metadata scrubbed on every output
  • A web page for people, a REST API for systems

Security & compliance →

Home turf

Built for the filings regulators expect.

Its home turf is US insurance rate, rule and form filings — the redline exhibits state regulators expect in SERFF submissions. The same primitives serve any regulated-document revision: utilities tariffs, FDA labeling, legislative amendments, bank disclosures, and more.

The SERFF use case All use cases

See it on your own filings

Bring two versions of a real filing — the demo lands in three minutes.

Ask for a walkthrough The full overview Documentation