Microsoft ended its Lens scanning app in March 2026, forcing users who relied on it for quick multi-page scans to find alternatives. But combining existing PDF files—whether signed forms, invoices, or e‑book chapters—has always been a separate challenge, especially on Windows where no built‑in tool handles it directly. This guide walks you through the most reliable, privacy‑conscious ways to merge PDFs on Mac, Windows, iPhone, iPad, and Android, using both free and premium tools.

What Changed With Microsoft Lens

On January 9, 2026, Microsoft began retiring its popular Lens mobile scanning app. Support ended a month later, and after March 9 new scans could no longer be created. The company directs users to the scanning feature built into its OneDrive app for Android (version 6.5 or later) and, for iOS, the native Notes or Files scanner. OneDrive’s scanner captures multi‑page documents—up to 10 pages—and automatically saves them as a single PDF, making it a decent replacement for turning paper into digital. But it doesn’t help you combine PDFs that already live in your Downloads folder or email attachments.

Most of us already have at least one pile of separate PDFs that need to be merged into a single, sequential document. The right method depends on your operating system, how often you do it, and whether the files contain sensitive data.

How to Merge PDFs on Every Platform

On a Mac: Preview and Finder Do the Job

Apple builds PDF merging into Preview and Finder, no extra software needed. Preview is the most flexible. Open the first PDF, choose View > Thumbnails to show the page sidebar, then drag another PDF from Finder directly into that sidebar. Drop it where you want the new pages to appear. You can also drag only selected pages by first opening both files and using the thumbnails in each window. Hold Command to pick non‑adjacent pages.

Important: Preview auto‑saves, so always choose File > Duplicate before you start editing. That way you keep the originals intact. Apple’s own support docs underline this; once you save over the original, there’s no way back.

Finder’s Quick Action “Create PDF” is faster when you just need to bundle whole files in a known order. Select the files in Finder, Control‑click, choose Quick Actions > Create PDF. The order follows selection order, so rename files with numeric prefixes (01‑Cover, 02‑Report) before you click. Quick Actions also appears at the bottom of the Finder preview pane if you’ve enabled it via View > Show Preview.

On Windows: You Need a Desktop PDF App

Windows 11, Microsoft Edge, and Microsoft Print to PDF have no built‑in workflow for merging existing PDFs. You must install a dedicated application. The three most dependable choices:

  • Adobe Acrobat (not Reader). The Combine Files tool is the gold standard: Menu > Combine files, add PDFs and even Word or Excel files, reorder thumbnails, expand any file to move individual pages, then click Combine. Acrobat also handles a mix of file formats in one step. The feature is only available in the paid version; if your work or school PC is managed, administrators can disable cloud services, hiding the Combine button. If you see it missing, use whatever PDF tool your IT department provides.

  • PDFsam Basic: A free, open‑source merger. Launch PDFsam Basic, choose Merge PDF, drag files into the list, arrange them, and click Run. It supports page ranges, bookmark handling, and form merging controls—handy when you need to combine reports while keeping internal structure.

  • PDF24 Creator: Also free, but more of a Swiss‑army knife. Drag files into the right pane, click the Join icon, and save. It can also compress, password‑protect, and watermark PDFs. The interface can overwhelm if you only merge once a month, but for regular office tasks it’s a reliable offline toolbox.

All three process files locally. That matters when the documents are tax returns, contracts, or anything protected by a privacy policy.

On iPhone and iPad: PDF Expert or Xodo

Mobile operating systems view and annotate PDFs, but assembling multiple existing PDFs into one calls for a specialist app. Two strong contenders:

  • PDF Expert by Readdle. From the file manager, tap Select, choose the PDFs, then tap Merge. On iPad, the Merge button lives in the sidebar; on iPhone, tap More to find it. The feature requires a subscription, though those who bought PDF Expert 6 before the subscription model can still merge without paying extra. A notable warning: merging signed PDFs or forms can break digital signatures and interactive fields. PDF Expert recommends flattening forms first—that is, creating a copy that turns fillable fields into static content—before merging.

  • Xodo: Works on both iOS and Android. Open the app, tap Toolbox > Manage PDF > Merge Pages. Select files, tap Next, reorder by dragging handles, then tap Merge. The interface is clean and consistent across platforms.

On Android: Xodo or OneDrive Scanning

For existing PDFs, Xodo’s mobile merge works identically on Android as on iPhone. If you’re starting from paper, use OneDrive’s scanner instead of creating a bunch of one‑page PDFs and merging later. Open OneDrive, tap the + (bottom left), choose Scan, pick the document mode, tap the capture button, then tap Add for each additional page. The final PDF is limited to 10 pages, but for insurance cards, receipts, and short forms, it’s a time‑saver.

Online Mergers: When the Browser Makes Sense

Every platform can also use an online service. You upload PDFs, rearrange them, click Merge, and download. Xodo, Adobe Acrobat Online, Smallpdf, iLovePDF, and PDF24 all offer browser‑based mergers that work on Windows, Mac, Linux, and Chromebooks. They’re a lifesaver on a locked‑down computer or when helping a relative remotely.

But they send your files to someone else’s server. For non‑sensitive documents—public flyers, generic forms, meeting handouts—the convenience is worth it. For anything confidential, stick with a local app. And remember: even if a service promises to delete files after processing, the responsibility remains yours to follow your organization’s data policies.

Steps to a Flawless Merge Every Time

Regardless of which tool you pick, a merged PDF is a new document that needs a final once‑over:

  • Verify page order: Open the file and scroll from start to finish. A cover page that ends up last is the most common mistake.
  • Check orientation: Landscape pages, especially printed Excel sheets, sometimes rotate during merge.
  • Confirm total page count: Match it against your mental tally. Missing a page is easy when you’re dragging 15 files.
  • Open on a second viewer: If you merged in Preview, open the result in Acrobat Reader or a browser. Different rendering engines can expose alignment bugs.
  • Inspect searchable text: Scanned pages are often just images. Use OCR (optical character recognition) if you need the text to be selectable. Tools like Acrobat and PDF24 Creator include OCR; others require a separate step.
  • Forms and signatures: As noted, interactive fields may vanish. Keep the original fillable form and only merge a flattened copy.
  • Rename the output: “Combined.pdf” tells nobody anything. Use a descriptive name: “2025‑Q4‑Expense‑Report‑with‑Receipts.pdf”.
  • Keep originals: A merged PDF is a distribution copy, not a secure backup. Store the source files separately.

Large file sizes can trip up email or web uploads. After merging, if the file exceeds 10–15 MB, use a compression tool (many of the desktop apps above include one). Then re‑check the compressed version to make sure images remain legible. Compression is always a trade‑off, and it’s frustrating to send a contract only to find the text is blurry.

Why Windows Still Lags on PDF Merging

macOS has offered PDF merging in Preview since … well, practically forever. Windows has never included a native merge tool, leaving a gap that third‑party developers have filled for decades. The difference stems from each OS’s approach to document handling: Apple treats PDF as a core system format, while Microsoft historically pushed its own XPS format and, later, PDF viewing but not editing. Even today, Microsoft Edge can annotate PDFs but not combine them; Print to PDF creates new files but can’t stitch existing ones. That’s unlikely to change—the third‑party ecosystem is too entrenched, and business users already have Acrobat. So Windows users will continue to rely on apps like PDFsam or Acrobat.

On mobile, the landscape shifted with Microsoft Lens’ retirement. Lens was never a PDF merger, but it did produce multi‑page scans. Now OneDrive shoulders that role on Android, and iOS Notes/Files on iPhones. Dedicated mobile PDF editors like PDF Expert and Xodo have added merging in response to user demand, making it possible to combine a handful of PDFs while standing in a coffee shop. The trend is toward consolidating features: fewer apps, more capability in each. Expect Readdle, Xodo, and others to keep refining their mobile merging workflows, especially for handling forms and signatures gracefully.

What to Do Next

If you’re still opening PDFs and trying to print them back into a single document, stop. That method rinses text, flattens everything into an image, and often scrambles order. Choose a proper tool instead.

  • Mac users: Use Preview for precision and Finder Quick Actions for speed. Duplicate first, merge second.
  • Windows users: Install PDFsam Basic or PDF24 Creator for free, offline merging. If you already have Acrobat, use its Combine Files tool.
  • iPhone/iPad: Get PDF Expert or Xodo. For signed documents, flatten a copy before merging.
  • Android: Use Xodo for existing PDFs; for new scans, open OneDrive and scan directly into a multi‑page PDF.
  • Everyone: Keep sensitive files offline. Use online mergers only when you know exactly what’s in the document and it’s not private.

Bookmark your chosen tool’s help page. Print the checklist above and pin it next to your monitor. Merge enough documents, and the steps become muscle memory. Until then, a little preparation saves the embarrassment of sending a client a 30‑page PDF with the table of contents on page 15.