XOR for Mac
Real-time PDF Comparison Viewer
¥2,000 *(tax included) per month
(subscription)
Free trial period 1 month
* Include a 10% sales tax in Japanese store
One-stop
proofreading
You can compare the PDF before and after the revision and add annotation comments to the difference areas. What’s more, you can export quality proof PDF (for proof submission) or DTP manuscript PDF for re-correction.
In other words, you can complete a series of proofreading tasks on XOR (*). For more details, please see the video here (in Japanese).
* A PDF viewer such as Acrobat is required to view DTP manuscript PDF.
About Quality
proof PDF…
A “Quality proof PDF” is a PDF file that certifies to the client, when submitting proofs, that “no changes have been made anywhere other than the sections requested for revision.”
If this PDF is attached when submitting proofs, the client can easily identify all changes and verify that no revisions have been overlooked and that no unnecessary changes have been made.
An example of a quality certificate PDF viewed in Acrobat.
You can add annotations for individual corrections directly in XOR
Require
Installation and execution of XOR requires macOS High Sierra or later.
Of course, the latest macOS Sonoma will also work without problems.
macOS Tahoe
macOS Sequoia
macOS Sonoma
macOS Ventura
macOS Monterey
macOS Big Sur
macOS Catalina
macOS Mojave
macOS High Sierra
XOR also works on Mac with Intel processors or Apple silicon.
Usage
Reading two PDFs
When you launch XOR, the PDF selection dialog will be displayed.
Please select two PDF files you want to compare, by click the [Open…] button. Or, you can drag and drop PDF from the desktop into the dark gray area of the dialog.
In this dialog, be sure to designate the PDF after the revision to the right side. This order is important when exporting the DTP manuscript for re-editing.
When you select PDF, a thumbnail of the first page and file information are displayed.
Please click the [OK] button. A document window appears, and the two PDF files are displayed side by side.
Twin pages view
Comparison
Twin pages view –> Overlapped pages view
Press the spacebar to switch to Overlapped pages. Overlapped pages is a composite of both PDF images. The red and blue areas are the differences. This is called the “Overlapped pages”.
Overlapped pages view
Overlapped pages view –> Thermography pages view
Press the space key again. Both PDF pages will be overlapped and merged. The red areas are the differences and the gray areas are the unchanged areas. This state is called “Thermography pages view”.
Thermography pages view
Thermography pages view –> Blink pages view
Press the space key again. Both PDF pages will continue to be displayed alternately. The part that appears to blink is the difference. This state is called “Blink pages view”.
Blink pages view
Blink pages view –> Twin pages view
Press the space key again. The window returns to “Twin pages view” with PDF pages lined up left to right.
Blink pages view
Identifying unchanged page
Pages and thumbnails that have not been modified are labeled “Unchanged.”
Please compare the DTP manuscript with each page in XOR.
This display state applies if there have been no changes to any pages
If a page in the DTP file that has revision instructions is marked as “Unchanged” in XOR, the revision has been overlooked.
If a page in the DTP file that has no revision instructions is not marked as “Unchanged” in XOR, the change is unnecessary.
Proofread
In Twin pages view, you can add annotation comments to the red lines marked in Overlapped view, Thermography view, or Blink view.
Display the Annotation Dialog
When you click on the red line you’ve marked, an annotation dialog box with a light red background will appear.
If further revisions are required based on the proofreading results
If revisions are needed in the relevant section, please enter your revision instructions starting from the third line where the cursor is located.
When you enter a revision instruction and close the annotation dialog box, the border changes to a red double line (indicating that a revision instruction has been entered).
If the proofreading results are OK
If the proofreading results are OK, click the green button in the annotation dialog.
The annotation dialog box closes automatically, and the border changes to a double green line.
In other words, you can submit your proofreading results with just one click. In fact, since most of the changes are marked as “OK,” the process is much faster.
Note that if you click on the green double-lined box to open the annotation dialog, a green sticky-note-like annotation dialog will appear, and the annotation comment will read “✔︎ OK.”
When you are unsure whether the proof is OK
Occasionally, after proofreading, you may be unable to determine whether the proof is OK or not, and you may need to check with the DTP operator. In that case, please click the yellow button.
The annotation dialog will change to look like a yellow sticky note.
When you enter the confirmation details starting from the third line and close the annotation dialog, the border will change to a double yellow line (indicating that the confirmation details have been entered).
Adding Annotations When Submitting Deliverables to Clients
Once production is complete and you are ready to submit the final PDF to the client, you may want to include some notes.
In that case, we recommend making the box yellow and entering the notes in the annotation dialog.
Please ensure that your comments are clear and easy for others to understand. These comments will serve as revision instructions for the DTP manuscript to be revised again, or as items to be reported in the PDF list of changes submitted to the client.
When entering proofreading results, it is best to avoid using emojis.
The Windows version of Acrobat cannot display annotation comments containing emojis properly (as of September 2025).
Comment counter
A three-color annotation counter is displayed in the upper-right corner of the window, and the number changes every time you add a highlight or enter an annotation (the default value is “- / -”).
The meaning of the counter is as follows.
When you have finished writing the annotation
When annotations are added to all boxes, the counter background is filled in and the numbers appear in white text.
In other words, you can immediately see at a glance whether there are any differences remaining where the proofreading results or annotation comments for the highlighted sections are incomplete.
Export DTP manuscript PDF for re-editing
If you find areas that need to be re-corrected during proofreading, export the DTP manuscript PDF for re-edit.
Excute “Export” > “Export PDF on the right side…” in the Fill menu.
This is an example of displaying an exported PDF in Acrobat.
Annotations written in XOR are carried over as annotations
in the PDF manuscript for re-editing
Exporting quality certification PDF
Once you have determined that the proofreading does not require re-correction, you should write out a quality assurance PDF. This PDF should be attached to your submission to the client to certify that you have not made any extra changes anywhere other than where you were asked to revise.
Excute “Export” > “Export PDF on the right side…” in the Fill menu
This is what the exported PDF looks like when opened in Acrobat.
Annotations written on XOR are carried over as annotations in the PDF
Subscription
If you use XOR for the first time, there is a 30 day free trial period. Subscription agreement is necessary to use it after that.
Tryal
If you use XOR for the first time, the subscription dialog is displayed.
Click on the “30 day trial version”. You can start the trial.
Subscribe
If you launch XOR after the 30 day trial period is over, the subscription dialog is displayed.
Click the “Monthly Subscription” button. You can subscribe to use the app.
Click the “Monthly Subscription” button. You can subscribe to use the app.
Select [Subscriptions…] from the [Help] menu.
Go to iTunes (Music app) and you will see a list of your subscribed apps.
Cancel your subscription.
Click the ［Cancel Subscription］ to cancel your subscription.
Expiration date
Select [Subscriptions…] from the [Help] menu. A dialog box will appear. You can check the date and time of your subscription renewal.
Please note that unsubscribe must be completed at least 24 hours prior to the renewal date and time.
FAQ
Price, Subscription, Purchase
How much is the price?
Subscription fee is ¥2,000(*) per month.
This contract is automatically renewed monthly, but you can cancel at anytime.
* Prices outside the Japanese store are determined by the exchange rate.
Is there a trial version?
Yes. If you use XOR for the first time, there is a 30 day free trial period. Subscription agreement is necessary to use it after that.
What are the advantages of subscription?
- The initial cost is relatively low
- You can cancel the contract when it is no longer needed. Therefore companies and organizations can control costs by increasing or decreasing team staff
- There is no additional cost to upgrade to the new version of the app
I can not find the subscription button on the Mac App Store
You can subscribe in the app.
How do I sign up for a subscription?
You can subscribe in the app. Please refer to “Subscribe“ above.
How can I cancel my subscription?
You can unsubscribe in the app. Please refer to “Unsubscribe“ above.
How can I confirm the the expiration date of subscription?
Please refer to Expiration date to confirm the expiration date of subscription.
Until when should I cancel my subscription?
Unsubscription must be completed 24 hours before the expiration date.
Please refer to Expiration date to confirm the expiration date of subscription.
Please refer to “Unsubscribe“ above.
Can companies and organizations subscribe for the number of staff?
Yes.
For details, please visit Apple’s business support page.
Utilizing the Apple Business Manager is a bit circuitous. You need to register your organization’s D-U-N-S number and also register an administrator.
So, why not pay 2,000 yen per month to all your staff who use XOR as an “app fee” instead? Then, have each staff sign up for a subscription.
I think the subscription monthly fee is too high…
XOR is an app for professionals who are not allowed to make trivial mistakes in production. Their number is limited. So we decided this price.
Moreover, we have many ideas of functions which could not be included in the current version of XOR due to priority reasons. We would be pleased if you understand that the price includes investment to realize them early.
Is there a packaged version?
No.
Can I purchase with a single payment?
No. It is only a subscription.
Can I purchase it outside the Mac App Store?
No.
Fnction, Specification
Which OS will run XOR?
The following versions.
- macOS Tahoe
- macOS Sequoia
- macOS Sonoma
- macOS Ventura
- macOS Monterey
- macOS Big Sur
- macOS Catalina
- macOS Mojave
- macOS High Sierra
Will XOR work on a Mac with Apple silicon?
Yes.
How much performance Mac is required to use XOR?
It’s okay with an entry level Mac. XOR is a very light app. However, when comparing PDFs with a large number of pages, the operation will be slower.
Is there a Windows version?
Yes. However, the Windows version does not yet have the one-stop proofreading feature. We will be releasing XOR for Windows with the same functionality as the Mac version in the near future.
For more information on XOR for Windows, please refer below.
Can I compare grayscale PDFs?
Yes.
Can I compare RGB color PDFs?
Yes.
Can I compare CMYK color PDFs?
Yes.
Can I compare spot color PDFs?
No. It may be possible, but it is not guaranteed.
Can I compare other than PDF?
No. If you want to compare images please convert it to PDF.
Does XOR send the PDFs for comparison to a server somewhere?
No. XOR completes the comparison process on the Mac. It does not have the ability to send the PDFs used for comparison to a server.
When comparing in XOR, the text in the PDF is different from how it appears in the original app…
It is possible that the font data is not embedded in the PDF.
Can XOR notify me “how has it changed” not only “where”?
No.
For example, we can develop software logic to analyze and compare between old PDF and new PDF. It is effective if the order and number of all elements in both PDFs are the same. However, if some elements are moved or new things are inserted during the modification, the logic may report an incorrect comparison result because wrong element pairing will occur.
Also, even if the logic accurately reports “where has changed”, humans have to verify that it has been modified as intended. This circumstance will not be solved until the artificial intelligence technology catches up with humans.
Therefore, XOR only judges “where has changed”.
Are you planning to release the next version?
The current version of XOR does not have the features I want.
We hope so. We have lots of ideas of unrealized features.
However, the timing of the upgrade depends on the revenue of this app. That day may come sooner if you have recommended XOR to your colleagues or person who works in the same field.
Others
How should I call “XOR”?
Please pronounce it as | eks | oʊ | ɑːr |.
What is the origin of the name “XOR” ?
It is “eXclusive OR”. We expressed it as exclusive OR about how to find differences by overlapping pages.
What is FROGFISH?
Frogfish is the name of a very popular fish in scuba diving.
About 50 kinds of members of Frogfish have been found. Some species of frogfish can hunt other fishes using their own fishing rods and simulated bait.
Privacy
XOR is an offline application. It does not collect or transmit personal information or data other than subscription procedures.
Personal data when someone is inquired from this website will be used only for user support.
Terms of Use
Last updated: October 25, 2019
This document is the terms of use for the application “XOR” provided by FROGFISH.JP. Please read the following carefully before using XOR.
If you do not agree to some of the terms, you can not use this app. By using this app, you are agreeing to these terms.
Subscription
XOR is provided with the subscription agreement. The subscription rate is ¥2,000 or equivalent amount in local currency par a month. The contract will be renewed automatically every month unless you turn off automatic renew option until 24 hours before the expiration. The fee will be charged to your iTunes account monthly. You can use XOR until the expiration after unsubscribe. No cancellation of the current subscription is allowed during active subscription period.
Free trial
If you use XOR for the first time, there is a 30 day free trial period. Subscription agreement is necessary to use it after that. If you subscribe within the trial period, the remaining trial period will expire.
Free change
FROGFISH.JP may modify the subscription fees by sole discretion. The new fee will be applied after next update of the agreement.
Refund
Except when required by law, paid subscription fees are non-refundable.