Apps & Software
A calm, jargon-free guide to the best free PDF tools for merging, splitting, signing, and shrinking files, plus how to pick safe, private options.
Nearly every everyday PDF job — merging, splitting, signing, filling a form, or shrinking an oversized file — can be done for free with software you already own: macOS Preview, Microsoft Edge plus "Print to PDF" on Windows, and the Notes and Files apps on your phone. Reach for a dedicated free app only for the few things the built-ins cannot do, and keep anything sensitive off random upload sites entirely.
Below is a task-by-task map of what handles each job well, with the exact menus and a few named tools worth trusting. Features shift with updates, so confirm the current details in the app before you rely on it.
Preview is the most underrated PDF tool on any Mac. Open a file, choose View > Thumbnails, and you get a page sidebar where you can drag pages to reorder, press Delete to remove them, or drag another PDF straight in to combine files. To sign, click the Markup icon (the pen tip), then Signature > Create Signature using your trackpad, camera, or iPhone. To fill a non-interactive form, use the Text tool from the same Markup bar. When you are done, File > Export as PDF writes a clean single file.
On Windows there is no Preview, but Microsoft Edge is a surprisingly capable PDF editor and is already the default handler. Open any PDF and the toolbar offers Draw, Highlight, Add text, and Erase — enough to fill forms and add a drawn signature. For creating PDFs, "Microsoft Print to PDF" appears as a printer in every app's Print dialog (Ctrl+P), so any document, web page, or email becomes a PDF. Edge cannot merge separate files, though — for that, see PDFsam or PDF24 below.
On iPhone, open Notes, tap the camera icon, and choose Scan Documents to turn paper into a straightened multi-page PDF; the Markup tools in Files and Mail let you sign a form without printing. To combine existing PDFs, the free Shortcuts app has "Make PDF" and "Combine" actions. On Android, Google Drive and Files by Google both include a Scan button (the + or camera icon), and any app's Share > Print > "Save as PDF" prints to a file. These built-ins keep the document on the device, which matters more than it sounds.
Most page-shuffling is done fastest in Preview's thumbnail sidebar — drag to reorder, drag files in to merge, drag a page out to the desktop to extract it as its own PDF. Windows lacks a native equivalent, so two free, offline apps fill the gap and cover almost everything:
Browser tools like iLovePDF, Smallpdf, and Sejda are convenient, but they upload your document to someone else's server. Sejda's free tier, for example, allows three tasks per hour on files up to 50 MB or 200 pages. Fine for a non-sensitive flyer; not where your bank statements belong.
There are two different things people call "signing." An electronic signature — a drawn or typed mark, like the one Preview or Adobe Acrobat Reader's free Fill & Sign adds — is legally valid for most agreements under laws such as the US ESIGN Act and the EU's eIDAS regulation. A digital signature goes further, attaching a cryptographic certificate that proves who signed and flags any later tampering; you only need it for high-stakes or regulated documents.
Two practical tips. First, if a PDF has real form fields, click straight into them; if it does not, add text boxes over the page rather than printing it out. Second, before you send a filled form, flatten it — printing it back to PDF (Microsoft Print to PDF, or Preview's Export) bakes your entries in so the recipient cannot edit or accidentally clear them.
PDFs balloon almost entirely because of embedded raster images, so compression works by downsampling those images to a lower resolution. That is why a scanned document shrinks dramatically while a text-only report barely moves — a common source of "why won't this get smaller" frustration.
-dPDFSETTINGS=/ebook (150 dpi, a good balance), /screen (72 dpi, smallest), or /printer (300 dpi, near-original).Aim for the largest file that clears your upload limit rather than the smallest one possible — over-compression turns text and photos mushy.
Microsoft Word opens PDFs directly: File > Open, pick the PDF, and Word reflows it into an editable document. It handles text-heavy files well and struggles with complex layouts. Google Docs does the same for free — upload to Drive, then open with Google Docs — and it will run OCR on a scanned page as it converts.
A password-protected PDF is genuinely encrypted (modern tools use AES-128 or AES-256), but there are two kinds of password. A user password is required to open the file and is the one worth setting. An owner password only restricts printing or copying and is trivially stripped by free tools, so never rely on it for real protection. In Preview, File > Export and tick Encrypt; on Windows, PDF24 or Stirling add a password offline.
A scan is just a picture until OCR (optical character recognition) adds a searchable text layer. Stirling PDF, PDF24, and Google Drive (open a scanned PDF with Google Docs) all do this free, most of them built on the open-source Tesseract engine.
The single most important habit: do not upload documents containing bank details, ID numbers, or signatures to a free website you found by searching "free PDF converter." Many are ad-choked, some push browser add-ons you did not ask for, and you rarely know how long they keep your file. Anything sensitive should be handled by an on-device tool — Preview, Edge, PDFsam, or a locally run Stirling PDF.
Two more mistakes worth avoiding:
The goal is not to become a PDF expert with a shelf of software. Start with what is already on your devices, add one focused free app — PDFsam, PDF24, or Stirling PDF — for the occasional job the built-ins miss, and keep private files on your own machine. Do that and the next merge, signature, or shrink is a few calm clicks rather than a hunt for expensive software.
For most everyday agreements, yes. A typed or drawn electronic signature is recognized under laws like the US ESIGN Act and the EU's eIDAS regulation. Only high-value or regulated documents typically require a certificate-based digital signature, which some employers or notaries provide.
Compression mainly shrinks embedded images, so a text-only or already-optimized PDF has little to remove. If your file is mostly text and still huge, the culprit is often embedded fonts or a hidden scanned image layer — running OCR and re-saving, or exporting through Print to PDF, can help.
For non-sensitive files, reputable ones (iLovePDF, Smallpdf, Sejda, Adobe's online tools) are generally fine and delete files after a set period. For anything with personal or financial data, use an offline tool instead so the document never leaves your device.
Usually not. Acrobat Reader's free Fill & Sign covers signing and form-filling, and free apps like PDFsam, PDF24, and Stirling PDF handle merging, splitting, compressing, and converting. Paid Acrobat mainly adds deep text editing and advanced redaction, which most people rarely need.
Kai tests far too many apps so you don't have to, and writes about the few that are genuinely worth your time and storage. A reformed app-hoarder, he's practical about features, privacy, and the difference between useful and merely shiny.
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