Help

Questions, answered
in plain words

Most of them come down to three: is it really free, where do my files go, and is that download safe. Those are first, and every answer here comes with something you can check for yourself rather than take on trust.

No account needed to read this, and no support ticket to open.

The basics

What Vuiso is, what it costs, and what it needs from you. Nothing, mostly.

What is Vuiso?

A set of free PDF tools that run inside your own browser instead of on a server.

Each tool is a single web page that does the whole job on your machine: merging, splitting, rotating, reordering, watermarking, turning pictures into a PDF, marking one up. You can use one straight from this site, or download it and keep it. Both are the same file doing the same work in the same place: your computer.

Who is behind Vuiso?

ARTRA DIGITAL KREASI, a small independent project from Indonesia.

Not a large company, and no investors waiting for fast growth or for your data to be turned into money. That is what makes the simpler route possible: tools that are genuinely useful, free, and respectful of the people using them. It is the same name you will see under the QRIS code in the tip jar.

What will Vuiso never do?

Four rules, with no exceptions.

  1. No uploads. Your file is never sent over the internet. Using a tool is like opening the PDF in Acrobat or any other PDF reader on your own computer.
  2. No accounts. No sign-up, no email address, no login.
  3. No ads. No banners, no trackers, no data sold to anyone.
  4. Works offline. Once the page has loaded, or once you have downloaded the tool, you can switch off the internet and keep working.

If Vuiso ever breaks one of these, it is no longer Vuiso.

Do I need an account, an email address, or a sign-in?

No. There is no account system at all.

There is nothing to register, nothing to confirm, and no free trial that expires. You open a tool and use it. Since we hold no account, there is also nothing of yours for us to lose in a breach.

Do I have to install anything?

No. Nothing is installed, and nothing is added to Windows or macOS.

If you download a tool you get an ordinary web page in a folder. Double-clicking it opens your normal browser, the same as opening a saved page. There is no setup wizard, no service left running, and no entry in your installed-programs list. To remove it, delete the folder.

What is the difference between "Launch" and "Download"?

Where the file sits. Not what it does with your documents.

  • Launch opens the tool here on the site. Quickest for a one-off job. Your PDF is still read and written on your own machine. The page comes to you; your file never goes back with it.
  • Download gives you the same tool as a file you keep. It works with no internet at all, on a USB stick, on a locked-down office laptop, for as long as you own the machine. Nothing can be taken away from you later.

One small technical difference favours Launch: served over https, the PDF renderer can start a proper background worker, so very large files preview a little faster than they do from a double-clicked local file. Everything else is identical.

Is it really free? What is the catch?

Free, all of it, with no catch to find later.

There is no paid tier, so nothing is being kept back from you: no ads, no watermark stamped on your output, no limit on file size or page count, no "you have used your 2 free tasks today", and no upgrade prompt standing between you and the Download button. If a tool can do something, it does it for you now.

Why is it free? How do you pay for it?

Because nothing is uploaded, there is almost nothing to pay for.

Online PDF services are expensive to run: your file has to be received, stored, processed on rented hardware and deleted again, for every visitor. That bill is what ads, subscriptions and sold data pay for. Vuiso does the work on your own computer or phone instead, so there is no server processing files to pay for. What is left is serving a few light pages, and that is currently covered entirely by Vercel's free hosting. That is why Vuiso can stay free for good, with no ads and no limits, honestly rather than by finding something else to sell.

If a tool saved you real time, there is a tip jar. Ignoring it entirely is a perfectly normal way to use Vuiso.

Which browsers does it work in?

Chrome and Edge are best. Firefox and Safari work too.

Any current version is fine, and you do not need a plugin or an extension. On very old browsers, such as Internet Explorer or anything several years out of date, a tool may open but fail to save the result, because saving a file from a page is a modern browser feature.

Does it work on a phone or a tablet?

It opens, and simple jobs work, but the tools are built for a mouse.

Merging a couple of files or rotating pages is fine on a tablet. Dragging thirty page cards into a new order on a phone screen is not a good time, and a large PDF can exhaust a phone's memory where a laptop would cope. Use the Launch link on a phone rather than downloading: phones make opening a saved .html file unnecessarily hard.

Does it work offline?

Yes. That is also the easiest proof that your files are not being sent anywhere.

  • The downloaded tool never needs the internet at all. On a plane, on a machine that has never been online, on a network with everything blocked: it works.
  • The Launch version needs the internet only to fetch the page itself. Once it has loaded you can disconnect and keep working, save your result, and nothing will complain.
What languages is Vuiso in?

English and Indonesian, throughout.

The site, the tools and this help page all exist in both. Use the EN / ID switch at the top of any page; the tools remember your choice per browser after the first time.

Privacy

The section that matters if you handle contracts, invoices, medical letters or anything with an ID number on it.

Are my files uploaded to a server?

No. Your file is opened and processed inside your own browser and never sent anywhere.

When you pick a PDF, the browser hands the tool the contents of that file in memory, in the same way a program installed on your computer would read it. The new PDF is built in memory too, then handed to your browser's normal save dialog. At no point does a copy travel over the internet, and there is no Vuiso server that could receive one if it did.

Put simply: an ordinary online PDF tool is like handing your document to a stranger and waiting for them to give it back. Vuiso is like working on it yourself at your own desk. We only supply the tools, and the document never leaves the house.

How can I prove that for myself?

Three tests, in order of how little you need to know.

  1. Unplug the internet. Switch off Wi‑Fi or turn on aeroplane mode, then use the tool as usual. It works normally. A tool that quietly sent your file to somebody's server could not possibly finish the job like this. That is the whole proof, and it takes ten seconds.
  2. Watch the network. If you know your way around a browser, press F12, open the Network tab, and use the tool. Nothing is sent. Not your file, not its name, not a single measurement of what you did.
  3. Read the lock. Every Vuiso page carries a Content-Security-Policy that forbids network connections outright. That rule is enforced by your browser, not promised by us: even if the code tried to send something, the browser would refuse and log the attempt.
Do you store, log, or even see my file names?

No. We never learn that your file exists.

File names, page counts, sizes, what you clicked, how long you stayed: none of it reaches us, because nothing is ever sent. There is no database of jobs, no "files are deleted after one hour" policy to take on faith, and no export queue where your document sits for a while. Nothing to delete, because nothing was ever received.

Do you use cookies, analytics, or advertising trackers?

No cookies, no analytics, no ad network, no third-party scripts of any kind.

This site does not even know how many people visited it. The tools store nothing between visits: closing the tab clears what you were working on, which is why a tool warns you before you close it with work in progress. The one thing a tool may remember is which language you chose, and that is kept by your own browser and never leaves it.

Can I use this for confidential documents, like contracts, ID cards or medical records?

That is precisely the case Vuiso was built for.

A PDF is rarely just a PDF: an employment contract, a scanned ID card or tax card, a financial report, a medical letter, an internal company document. With an ordinary online converter, a document like that leaves your control the moment you press Upload: it sits on somebody else's disk, is handled by their staff and their backups, and is subject to their jurisdiction. All you have is their promise to delete it within a few hours. With Vuiso the document behaves like a file you opened in a program on your own laptop, because that is what happened. That is not a promise either: you can check it yourself. For the strictest cases, download the tool and run it on a machine that is offline; then there is not even a page load to think about.

What happens to my work if I close the tab?

It is gone, on purpose.

Nothing is written to a database, a cloud drive, or your browser's storage, so there is no half-finished document of yours left lying about anywhere. The cost of that is real: an arrangement you have not exported yet is lost when the tab closes, which is why the tools ask before letting you close one. Save the result first.

Our IT department blocks online PDF tools. Is Vuiso different?

Yes, and it is different in exactly the way those rules are usually written to care about.

Such policies exist because uploading a company document to an outside service is a disclosure of that document. Vuiso performs no upload. There is no destination, and the page is locked down so the browser itself would block one. Show your IT team the two facts they can verify in a minute: the tool completes a merge with the network disconnected, and the page's Content-Security-Policy sets connect-src 'none'. Many teams are happiest with the downloaded copy, kept on an internal file share and checked once against its SHA-256.

What about GDPR, or data-protection rules generally?

Vuiso collects no personal data, so there is none to process, transfer or breach.

Rules of that kind govern what an organisation does with data it receives. We receive nothing: no account, no email address, no analytics, no file. The pages themselves are served by Vercel, which, like any web host, handles the ordinary request for a page, but never your document, because your document is never sent. It stays under your own control from beginning to end, which is the strongest position any of these frameworks recognise.

Is the download safe?

A fair thing to ask of any free download. Here is exactly what you are getting, and how to check it without trusting us.

Is the ZIP file a virus, or does it contain one?

No, and the reason is structural, not a promise: there is no program inside it to be one.

A virus has to be something that runs: an .exe, an .msi, a .bat, a macro-carrying document. The Vuiso ZIP contains none of those. It holds one web page and three plain text files. Opening it starts your browser, exactly like opening any website, except that this page is on your own disk and is forbidden from talking to the network. It cannot install anything, cannot start at boot, cannot touch files you did not choose, and cannot run when the browser is closed.

What exactly is inside the ZIP?

Four files in one folder. You can look before you unzip: every ZIP viewer lists the contents.

FileWhat it is
Vuiso <Tool>.htmlThe tool itself: one self-contained web page, 0.8–2.5 MB
HOW TO USE.txtThe manual, in plain text
LICENSES.txtLicence terms, including the open-source parts used inside
…sha256.txtThe fingerprint you can check the tool against

No installer. No setup file. No folder of mysterious components. If what you unzip does not look like this, it did not come from us, so delete it.

My browser warned me about the download. Should I worry?

No. That warning is about popularity, not about content.

Chrome and Edge show "this file isn't commonly downloaded" for any file that few people have downloaded yet. It is a reputation counter: a brand-new file from a small independent site starts at zero and stays there until thousands of people have fetched it. A large company's installer never sees the message, and buys its way past it with a code-signing certificate costing several hundred dollars a year, which is a statement about a budget, not about safety.

What to do Choose Keep, then verify rather than trust: check the SHA-256 below, and scan the file with your own antivirus or at virustotal.com. Both take under a minute and prove more than any warning label could.
My antivirus flagged it. What now?

Do not ignore it. Check it, and tell us if it is real.

Occasionally a scanner reports a single generic detection on a large HTML file, usually with a name like Heur or Generic, because the tool packs a lot of compressed JavaScript into one file and that shape resembles obfuscation. Upload the file to virustotal.com, which runs it past seventy engines at once. One lone hit among seventy is the classic signature of a false positive; several agreeing hits are not, and in that case the copy you hold is not the one we published.

Either way, run the fingerprint check next: it is the definitive answer to whether your copy is the published one.

How do I check the file has not been tampered with?

Compare its SHA-256 fingerprint with the one printed on the download page.

A fingerprint is a long code calculated from the contents of a file. Change one byte anywhere in it and the code changes completely, so if yours matches ours, your copy is bit-for-bit the one we published. Nothing was injected on the way to you, by a network, a mirror, or anything else.

Unzip first, then in the folder holding the .html file:

Windows certutil -hashfile "Vuiso Merge PDF.html" SHA256 macOS/Linux shasum -a 256 "Vuiso Merge PDF.html"

Compare the result with the value on that tool's page, and with the .sha256.txt file sitting next to it. Letter case does not matter; every other character must match.

Can I keep it on a USB stick, or pass it to a colleague?

Yes. Keep your own copy, run it offline, and pass the unmodified file to a colleague or friend.

That is exactly what the licence allows, and it is a good way to work: an office with no internet, a client's laptop, a machine locked down by IT. What the licence does not allow is republishing or rehosting it as your own download or web service. See the licence question.

Can I see the code? Is it open source?

You can read every line that runs on your machine, but Vuiso is not open source.

The tool is a single HTML file: open it in Notepad or any text editor and the entire program is right there. There is no hidden second half and no server component, because there is no server. That is a stronger guarantee than most installed software offers, where the code you run is a compiled binary you cannot inspect at all.

The two open-source libraries inside (Mozilla's pdf.js for reading PDFs, pdf-lib for writing them) are named with their licences in LICENSES.txt. Vuiso's own code is proprietary: free to use, not to republish or build a competing product from.

Why is a single web page 2.5 MB?

Because everything it needs is inside it, including a complete PDF engine.

Reading and writing real PDFs is genuine work, and the two libraries that do it are the bulk of that size. Bundling them into the one file is what lets the tool run with no internet, no install and no downloads happening behind your back. Image to PDF is only 0.8 MB because it never opens a PDF, so it ships the writing half alone.

Using the tools

What they will do, what they will not, and the limits that are real.

Is there a file-size limit, or a limit on how many files?

No limit is imposed. The only ceiling is your computer's memory.

Online services cap you because every megabyte costs them bandwidth and disk. Nothing here is uploaded, so nothing is metered. In practice a job of a few hundred megabytes is comfortable on an ordinary laptop; as a rough guide, allow around 300 MB plus seven or eight times the total size of what you are working on. Under 50 MB you will never think about it.

Will merging, splitting or rotating reduce quality?

No. Page content is copied across untouched, never re-encoded.

Text stays text, vector drawings stay vectors, images keep their original data. A searchable PDF is still searchable afterwards and you can still select and copy from it. Nothing is flattened into a picture, and nothing is compressed a second time.

Can it open password-protected PDFs?

No. An encrypted file is reported and skipped, and the rest carry on loading.

Remove the protection first in whatever program you use to open the document, save an unprotected copy, and use that. Vuiso will not ask you for a document password, and no Vuiso tool removes or cracks one.

What happens to form fields and digital signatures?

The visible page survives; interactive form fields and digital signatures do not.

This is a property of rebuilding a PDF, not a shortcoming of these tools: any merge or page-level edit breaks a signature, because a signature certifies the exact file it was applied to. If a signature matters, do your merging and reordering first and sign at the end.

Can it make a scanned PDF searchable, or extract its text?

No. There is no OCR in Vuiso.

A scan is a picture of a page, and turning that back into text is a different kind of job. You can merge, split, rotate, reorder and watermark scanned pages perfectly well. The pictures are simply carried across as they are.

Can I edit the existing text in a PDF?

No. PDF Editor adds things on top of a page; it does not rewrite what is already there.

It is a markup tool: notes, arrows, shapes, measurements and dimensions with CAD-style snapping, laid over the original. Correcting a typo in the underlying document means going back to whatever produced the PDF. Tools that claim to edit PDF text usually rebuild the page and quietly ruin its fonts and layout.

Where does the finished file go?

Wherever your browser saves downloads, usually your Downloads folder.

The result is handed to your browser as a normal download, so your own settings decide. If your browser is set to ask each time, you get a Save As dialog and choose the folder yourself.

Are my original files changed?

Never. They are not even opened for writing.

Every tool reads your file and writes a new one. The original stays exactly as it was, byte for byte. Nothing is renamed, moved, or overwritten in place.

Can I undo?

Yes. Ctrl+Z to undo, Ctrl+Y to redo.

Every arrangement step is undoable, so trying an order costs nothing. Removing a whole file from a job is the exception and asks first, because undo does not cover it: the file would have to be read from disk again.

It is slow, or it ran out of memory on a big file.

The work is happening on your machine, so a heavy job asks something of it.

  • Close other tabs. A browser divides memory between them, and a video call or a spreadsheet in another tab is competing with you.
  • Use Chrome or Edge for very large jobs; they handle big allocations best.
  • Split the work: merge in two halves, then merge the halves.
  • Prefer a laptop over a phone once files get past a few tens of megabytes.

Only the first page of each file is ever drawn as a preview, never every page, which is what keeps large sets manageable at all.

Which tool do I need?

Several of them look alike from the outside. This is the difference in one line each.

Merge, Split or Organize: they all sound the same

They differ in what you are moving: whole files, or pages.

ToolUse it when
Merge PDFYou have several PDFs and want one, in an order you choose. Whole files.
Split PDFYou have one PDF and want to drop pages from it, or pull a few out into their own file.
Organize PDFYou want the pages themselves in a different order: dragged about, deleted, or slotted in from another PDF.
Some pages came out sideways, but not all of them

Rotate PDF: one page at a time, or all of them at once.

The usual case after scanning a stack that went through the feeder the wrong way up. The rotation is written into the PDF itself, so it stays that way everywhere the file is opened.

I have photos or screenshots, not a PDF

Image to PDF: pictures in, one PDF out, one picture per page.

JPG, PNG and WebP, arranged in the order you set. Handy for phone photos of a document, receipts, or a set of screenshots that needs to become one attachment.

I need to stamp "CONFIDENTIAL", or put my logo on every page

Watermark PDF: a word or an image, over the pages or behind them.

Angle, size, opacity and tiling are all yours to set, with a live preview laid out the same way the export is, so what you see is what gets written.

I need to write notes, arrows or measurements on a drawing

PDF Editor: markup and dimensioning with CAD-style snapping.

Built for plans and technical drawings as much as for documents: shapes, text, arrows and real measurements that snap to the geometry already on the page.

When something breaks

The handful of things that actually go wrong, and what fixes each one.

I double-clicked the file and nothing happened, or the page is blank

Almost always one of two things: it was never unzipped, or it opened in the wrong program.

  • Unzip it first. Windows lets you look inside a ZIP as though it were a folder, but a tool opened from in there may not run. Right-click the ZIP, choose Extract All, and open the file from the real folder that appears.
  • Open it with a browser. If a code editor or Notepad opened instead, right-click the .html file, choose Open with, and pick Chrome or Edge.
  • Still blank? Use the Launch link on the tool's page. If that works, the problem is local to the file, not the tool.
The download did not start, or I got an HTML file instead of a ZIP

Usually an office network or an extension intercepting the download.

Try a different browser, or a different network. A mobile hotspot settles it quickly. Some corporate filters block ZIP downloads outright; in that case use the Launch link instead, which needs no download at all.

It says my file is damaged or password-protected

The PDF is encrypted, or it really is corrupt.

Open it in your usual PDF reader. If it asks for a password there too, remove the protection and save an unprotected copy. If your reader also complains, the file was damaged before it reached Vuiso, so re-download or re-export it from wherever it came from.

The tab froze or crashed partway through

Memory. The job asked for more than the browser could give it.

Close other tabs and try again, or split the work into two smaller jobs and combine the results. Chrome and Edge cope best with very large files. Your original files are untouched by a crash, because nothing was being written to them.

It behaves differently in Firefox or Safari

Both work, but Chrome and Edge get the smoothest ride.

Differences show up in the corners: how the save dialog behaves, how quickly previews appear, how much memory a very large job is allowed. If something looks wrong, try the same job in Chrome or Edge before assuming the file is at fault.

Drag and drop does not work

Use the button instead. It does exactly the same thing.

Dropping files onto a page is blocked in a few situations: some remote-desktop sessions, some managed browsers, and files dragged from inside a still-zipped folder. "Add PDF" (Ctrl+O) accepts several files at once and never has this problem.

The result is not what I expected

Check the confirmation summary. Every tool shows one before it writes anything.

It lists what is about to happen: how many files, how many pages, the order they will be written in, and the output name. Nothing is written until you press the button in that window, so it is the moment to catch a wrong order. And your originals are never modified, so a bad result costs you nothing but another attempt.

Nothing here matches that. Try a shorter word, or ask, and the answer will end up on this page.

Still stuck?

If your question is not here, it belongs here. Write to hello.vuiso@gmail.com and the answer gets added, so the next person finds it without having to write to anyone.

Buy me a coffee

Vuiso tools are free and always will be. If one saved you time, a coffee helps keep them maintained.

QRIS payment code
QRIS, Gerbang Pembayaran Nasional
ARTRA DIGITAL KREASI

Works from any Indonesian banking or e-wallet app.