日本語
Okinawa Software Lab

Your PDFs never leave your PC.

We make small PDF tools — and a free file checker — for Windows, from Okinawa, Japan. Sort and print, mark up and redact, check before you send, know what a file is before you open it. Nothing you open is ever uploaded. All four are on the Microsoft Store.

Fully offline Originals untouched One-time purchase English / Japanese Windows 10 / 11
Apps

Four tools, four jobs

Rather than one app that tries to do everything, each tool takes one problem and makes it something anyone can handle.

PDF Sort & Print icon

PDF Sort & Print

Stop opening files one at a time just to print them.

  • Drop in as many PDFs and images (JPG/PNG) as you like, put them in order, and print the whole set in one pass. Whole folders can be dropped in too.
  • Order them by date added, date modified, document date, natural filename order (2 comes before 10), or by hand. One click reverses any of them.
  • Document date reads each photo's capture time and each PDF's creation date, so copying files never scrambles the order.
  • Print directly and no combined file is left behind — nothing to clean up afterwards when the documents hold personal data.
  • Hundreds of files sort instantly: 300 files in a few seconds.
Price
Free — every feature, today
A future version may turn batches of more than 10 files into a paid option. Up to 10 files will stay free.
Get it on Microsoft Store
PDF Markup & Redact icon

PDF Markup & Redact

Mark it up. Black it out. Print it.

  • Fix existing text. Click any text in the document to cover it in white and retype it in place — like correction tape on paper. Font, size and colour are matched automatically, and clicking the new text again lets you adjust it on the spot.
  • Highlighter, underline, boxes, text, shapes and speech balloons. Text can carry a shadow or an outline. Phrases you use often can be saved as templates.
  • Fourteen stamps and a date stamp, plus your own images — a signature or a seal — placed as stamps.
  • Redaction is free: white-out, black-out, mosaic, or fill with colour. Pages are flattened to images when you save, so the text underneath does not come back.
  • Even on scanned documents, a click selects the text automatically — the text recognition also runs entirely on your PC.
  • Rotate, crop, brighten photos, present full screen, delete pages, or start from a blank sheet (A4/A3/B5/Letter/Legal).
  • Split a single page across several sheets: split printing and poster printing.
  • Open files by drag and drop.
  • SVG images open too, and transparent SVGs work as image stamps.
Free
Everything except saving and printing — redaction included
Pro
One-time purchase — save as PDF, save as JPG, print, split printing
The price for your country is shown on the Microsoft Store. There is no subscription.
Get it on Microsoft Store
PDF Privacy Checker icon

PDF Privacy Checker

Are you certain that redaction removed anything?

  • A black box drawn over a name often hides it only from your eyes. Copy and paste — or an AI assistant — can still read what sits underneath.
  • In PDFs it finds: text in the same colour as the background, transparent text, text behind images and shapes, text outside the page, microscopic text, annotations, form field values, document properties, and text left behind in earlier revisions.
  • In photos it finds: GPS location, capture time, camera model, author name, and the thumbnail of the unedited shot that EXIF quietly keeps.
  • For files you receive, it reads the editing history and signs of AI generation. It never accuses anyone — it lists the records that are actually there.
  • Reports carry the full body text as an appendix, with the hidden text mixed in and colour-coded so you can see exactly where it was.
  • This app has no ability to alter your original file. Removing anything always produces a separate copy.
Free
Every check, and everything it found — you can see what is inside without paying
Pro
One-time purchase — save reports, create a cleaned copy, X-ray view, GPS coordinates and map, history analysis
The price for your country is shown on the Microsoft Store. There is no subscription.
Get it on Microsoft Store
File Type & Safety Checker icon

File Type & Safety Checker

Know what a file really is before you open it.

  • “What is this file?” “Is this attachment safe to open?” — drag & drop any file and get the answer in plain language. Works on files that will not open, or that show a blank white icon.
  • About 180 extensions recognised. About 70 formats are verified from the file's signature, so a faked or stripped extension does not fool it. Program files are named by language (about 40 languages).
  • Lost the extension? The app identifies the file from its contents, estimates the original extension and — if it is safe — opens it for you.
  • Warns about double extensions (“invoice.pdf.exe”) and executables dressed up as documents or images. Detects macros in Word / Excel files.
  • Shortcut (.lnk) targets are shown. A shortcut wearing a document icon that launches PowerShell hidden, or one named “invoice.pdf.lnk” that points elsewhere, is marked Danger. Downloaded files also show their source (Windows' Mark of the Web). New
  • Executables get an identity check: digital signature (with the signer's name), the company and product they claim to be, and when they were built.
  • Documents and photos show who made them, when, and with what in one line. Images show their size, videos their length.
  • Check a whole folder at once. Results are sorted most-dangerous-first and can be viewed, saved or printed as a single report.
  • Files are only read. Fully offline — nothing about them is ever sent anywhere. English and Japanese. It inspects files before you open them; it is not a replacement for antivirus.
Free
Everything is free — the check itself will always be free
Get it on Microsoft Store
Articles

Articles

Write-ups on how the apps work under the hood, published on DEV Community. Per-app release notes live on each app’s Microsoft Store page.

All articles on DEV →

Principles

The same three promises, in every app

Fully offline

Nothing you open is sent over the internet — not a page, not a thumbnail. Every operation finishes on your own machine. The only time an app talks to a server is when the Microsoft Store handles a purchase or confirms that you own Pro.

We never touch the original

Your file is never silently rewritten or deleted. When something has to be removed, a separate copy is created. Evidence, deliverables and records cannot be destroyed by a mis-click.

Bought once, yours

Every paid version is a one-time purchase. No subscriptions. The purchase lives on your Microsoft account, so a new PC or a clean reinstall never means paying again.

FAQ

Questions we get

Is any part of my document uploaded?

No. These are desktop applications, not web services. The contents of the files you open never leave your computer — you can disconnect from the network entirely and every feature still works. The one exception is the Microsoft Store purchase flow, which handles payment and licence checks and never sees your documents.

Do I need to create an account?

No. There is no sign-up, no login and no telemetry. If you buy a Pro version, that purchase is recorded against the Microsoft account you already use for the Store — the same as any other Store app.

Will Windows warn me when I install?

No. All four are distributed through the Microsoft Store and reach you signed by Microsoft, so you will not see the blue warning screen that appears when running a downloaded .exe.

Is there a Mac or mobile version?

Not at the moment. Windows 10 and 11 only.

Will PDF Privacy Checker find every possible way of hiding something?

No, and we would rather say so plainly. It detects the common techniques, but file formats are endlessly varied and no tool can promise to catch everything. Text that has been baked into an image — a photograph of writing — is outside its scope. Treat it as a strong last check before you send, not as a guarantee.

Who makes these?

Okinawa Software Lab, a small independent developer in Okinawa, Japan. The tools grew out of everyday office work: too many files to print one by one, and documents that had to be checked before they went out of the building.

Contact

Get in touch

Bug reports, questions and "I wish it could do this" are all welcome by email or through the form below. Requests genuinely shape what gets built next. The same form opens from the Contact button inside each app.

Email — info@okinawasoftwarelab.com English form