Beta
Review Report
Every change becomes a card with before, after and difference pictures. Add a review decision and a note to each one, and the reviewer name and a key plan. Then export a PDF, checking it page by page in the preview.
Stop hunting for what changed in your drawings.
REVIFF compares two versions of a drawing set on your Windows PC and marks every change with revision clouds. Drawings are never uploaded to AEC DX Labs.
Version 2.0.0.0 · Windows 10 / 11 · PDF + images · English / Japanese
Split mode puts the two versions side by side. Diff mode shows removed content in red and added content in blue (the default in English; the Japanese preset swaps them, and you can change the colors). Recorded in the early PDF Diff beta: REVIFF 2.0 looks different, but compares the same way.
REVIFF 2.0
What's new in 2.0
The core works just as in 1.0: compare, Classic clouds and export, with no account. 2.0 adds Beta features for the review itself, and makes compare and export easier.
Beta · Optional
AI review by Claude or Gemini
AI describes each change, writes a digest for each sheet and sums up the whole revision. Use Claude in the Claude Desktop app (Connect Claude in Settings), or Gemini with your own Google API key.
Beta
ShapeFit clouds
Clouds that follow the shape of each change and merge where they overlap, so busy drawings stay readable. Choose Balanced or Detailed.
Activate Beta features once
Use your email and a 6-digit code, or Google or Microsoft. No password. After that, Beta features also work offline for up to 30 days. They may change or be removed later.
A 1-minute quick tour
The tour ends on a finished sample with Claude's summary, review decisions and notes. Try the decisions yourself, and open the tour again any time from Help.
Also in 2.0
Compare and export
- Auto-align before compare, on by default.
- Compare areas: ignore an area, or compare only inside it.
- More than one PDF or image per side.
- Overlay mode with a Before/After fade, and Added / Removed / Unchanged layers.
- A new export dialog with a page-by-page preview.
- Exported diff results carry a color legend, file names and the date.
The app
- A What's new window when you update.
- If REVIFF closes unexpectedly, it offers to restore your work.
- Account: your name and photo, your PCs, and backups of color presets and export settings.
- News, bug reports and support questions inside REVIFF.
- New menu bar and Settings window, with Light and Dark themes.
- Faster startup and lower memory use.
The core
Three features that do the heavy lifting
Alignment that works. Differences you can read. Clouds that are ready to hand off. All three work without an account.
Auto-align
Pages don't line up?
One click to fix it.
REVIFF 2.0 aligns pages before it compares them (on by default). If a page still looks off, run Auto-align again: it corrects scale and offset, then compares again cleanly.
Partial Align
Only part of the page moved?
Crop it. Realign just that area.
Select a region and realign just that area independently. Works when different parts of a sheet were revised at different scales or positions.
Cloud marks
Where exactly did it change?
Every change, circled automatically.
REVIFF finds the changed regions and draws revision clouds around them, the standard way to mark a revision. Classic clouds are part of the core; ShapeFit clouds are a Beta feature. Export is ready to hand off.
Why free
Why REVIFF is free
REVIFF began as PDF Diff — a personal workflow research project built by an architectural designer in Tokyo under AEC DX Labs, to test whether manual revision checking could be simplified without changing how teams already work.
The core comparison tool is free. The goal is research and practical value for the AEC community.
REVIFF continues that research — now on Microsoft Store, free for personal and commercial use.
What needs an account
Compare without an account.
The core needs no account. Beta features need a one-time activation. AI is optional.
The core
No accountCompare, Classic clouds and export work as in 1.0. Open REVIFF and start. Drawings are never uploaded to AEC DX Labs.
The core comparison costs nothing and needs no account.
Beta features
One-time activationShapeFit clouds, the Review Report and AI review. Activate Beta features once with your email and a 6-digit code, or with Google or Microsoft. No password.
After that, they also work offline for up to 30 days. Beta features may change or be removed later.
AI review
OptionalUse Claude in the Claude Desktop app, through REVIFF's local extension, or Gemini with your own Google API key. Or leave AI off.
Only the pictures and text of the changes you analyze go to Gemini. Claude reads the report through Claude Desktop, under your own Claude account.
How AI handles your dataSigning in to your AEC DX Labs account also shows your name and photo in REVIFF, lists your PCs, and backs up your color presets and export settings.
Quick Answers
Short answers to the questions people ask first.
Never uploaded
Your drawings
REVIFF compares drawings on your Windows PC. They are never uploaded to AEC DX Labs.
No account
Core comparison
Compare, Classic clouds and export work without an account. Beta features need a one-time activation.
Microsoft Store
Install and updates
Install and update from Microsoft Store, on Windows 10 (1809 or later) or Windows 11, 64-bit.
Do I need an account?
Not for the core. Compare, Classic clouds and export work without one. Beta features (ShapeFit clouds, the Review Report and AI review) need a one-time activation with your email and a 6-digit code, or with Google or Microsoft.
Does REVIFF upload drawings?
No. Drawings are never uploaded to AEC DX Labs. If you choose Gemini for the optional AI review, the pictures and text of the changes you analyze are sent to Gemini.
What file types can it compare?
PDF and common image formats: PNG, JPG, JPEG, BMP, GIF, TIF and TIFF. You can load more than one file per side.
FAQ
Trust and FAQ
Core trust signals stay visible alongside the questions people ask first.
Common Questions
Do I need an account?
Not for the core. Compare, Classic clouds and export work without one. Beta features (ShapeFit clouds, the Review Report and AI review) need a one-time activation with your email and a 6-digit code, or with Google or Microsoft.
Does REVIFF upload drawings?
No. Drawings are never uploaded to AEC DX Labs. If you choose Gemini for the optional AI review, the pictures and text of the changes you analyze are sent to Gemini.
What file types can it compare?
PDF and common image formats: PNG, JPG, JPEG, BMP, GIF, TIF and TIFF. You can load more than one file per side.
Do I have to use AI?
No. AI review is optional. You can use Claude in the Claude Desktop app, or Gemini with your own Google API key, or leave AI off.
What does Beta mean?
Beta features are new and still being refined, so they may change or be removed later. Once activated, they also work offline for up to 30 days.
Why Microsoft Store only?
Microsoft Store keeps install, updates, and product identity clearer for Windows users.