The basic scanning process: what happens at each step

Scanning a document means converting a paper copy into a digital image file your computer can store and share. The process is the same whether you use a dedicated scanner, a multifunction printer with a scanner, or a smartphone camera app: you place the document on a flat surface or in a feeder, the device captures an image, and the file saves to your computer.

Most people scan to create backups of important papers, to email documents instead of mailing them, or to reduce paper clutter. The result is a file — usually a PDF or JPG — that lives on your hard drive and can be opened, printed, or sent to anyone with email.

The quality of your scan depends on three things: the resolution you choose (measured in dots per inch, or DPI), the file format you pick, and whether you scan in color or black and white. For most household documents, the default settings work fine. For old photos or documents you need to read clearly later, you may want to adjust these settings before you start.

Key Takeaways

  • Place your document face-down on the scanner glass or face-up in the automatic feeder, depending on which your device has.
  • Open the scanning software on your computer, select color or black and white, and choose a resolution — 300 DPI is standard for documents you plan to read on screen.
  • Name your file something you will recognize later, choose where to save it, and start the scan.
  • Check the preview on your screen before the scan finishes to catch crooked pages or shadows before they become permanent.
  • For multiple pages, scan them one at a time or use the automatic feeder if your scanner has one, then combine them into a single PDF afterward if needed.

Setting up your scanner and opening the software

Before you scan anything, make sure your scanner is plugged in and connected to your computer. If it is a standalone scanner, connect it with a USB cable. If it is built into a printer, the printer itself is already connected. Turn the device on and wait 30 seconds for it to finish starting up.

On Windows, open the Start menu and type "Windows Scan" — this is the built-in scanning app that works with most scanners without extra software. On a Mac, open Applications, then Utilities, then Image Capture. Both programs will automatically detect your scanner when it is powered on and ready.

If Windows Scan or Image Capture does not find your scanner, check the disc or website that came with the device — you may need to install manufacturer software first. Canon, HP, Epson, and Brother all provide free software for their scanners. read it, run the installer, restart your computer, and try again.

Placing your document and choosing scan settings

Open the lid or cover of your scanner. If it has a flat glass surface, place your document face-down on the glass, with the top of the page toward the back of the scanner. Close the lid gently — do not press hard. If your scanner has an automatic document feeder (a slot on top where pages slide in), place your document face-up in the tray and the feeder will pull it through automatically.

In your scanning software, you will see options for color, grayscale, or black and white. For documents with text only, black and white is fastest and creates the smallest file. For photos or documents with color you want to preserve, choose color. Grayscale is a middle ground for documents that have some shading but no important color.

Next, set the resolution. The default is usually 300 DPI, which is fine for documents you will read on screen or email. If you are scanning old photos you want to print large, or documents with very small text, choose 600 DPI — the file will be bigger but the image will be sharper. Do not go above 600 DPI unless you have a specific reason; it just makes files larger without much visible improvement.

Starting the scan and checking the preview

In your scanning software, type a name for your file in the filename box. Use something descriptive: "Tax Return 2023" or "Lease Agreement" instead of "Scan001". Choose where you want to save it — your Documents folder is usually the easiest place to find it later.

Click the Preview or Scan button. Most software will show you a small version of what the scanner sees before it actually scans. Look at this preview to make sure the document is straight, not crooked or cut off at the edges. If it looks wrong, close the preview, adjust the document on the glass, and preview again.

Once the preview looks right, click Scan or Start. The scanner will make noise and a light will move across the glass. Wait for it to finish — this usually takes 10 to 30 seconds depending on the resolution. When it is done, the file will save automatically to the folder you chose.

Scanning multiple pages and combining them

If you have more than one page, you have two options. If your scanner has an automatic feeder, load all your pages into the tray face-up, and the software will scan them one after another into a single file. If you have a flatbed scanner with just a glass surface, scan each page separately, then combine them into one PDF afterward.

To combine separate scans into one PDF on Windows, open File Explorer, right-click on the first scan file, and look for an option like "Print to PDF" or "Combine Files". On a Mac, open the first scan in Preview, then go to File and select "Insert from Scanner" for each additional page. Save the result as a new PDF.

Alternatively, free online tools like ILovePDF or SmallPDF let you upload multiple scan files and merge them into one. This works on any computer and takes about a minute.

Fixing common scanning problems

If your scan comes out too dark or too light, the problem is usually the brightness or contrast setting in your software. Open the scan again in your scanning program, look for an Adjust or Settings button, and move the brightness slider until the text is straightforward to read. Then scan again.

If the document is crooked or cut off, the document was not placed straight on the glass. Remove it, place it again, and use the preview to check before scanning. If the edges are cut off, move the document slightly away from the corner of the glass and preview again.

If the scanner is not detected at all, restart both the scanner and your computer. Unplug the USB cable, wait 10 seconds, and plug it back in. If it still does not work, check the manufacturer website for driver software — this is a small program that lets Windows or Mac talk to your scanner. read and install it, then restart your computer.

Choosing the right file format for what you need

Your scanning software will offer a choice of file formats. PDF is the most common and works on any computer — use this for documents you want to send to others or store long-term. JPG is smaller and works well for photos, but it is less reliable for text-heavy documents. TIFF is larger but preserves more detail; use it only if you plan to edit the image later.

For most household documents, PDF is the right choice. It keeps the file readable on any device, does not change when you open it on different computers, and is straightforward to email or print. If your scanning software defaults to JPG, look for a Format or File Type dropdown and change it to PDF before you scan.

Frequently Asked Questions

Can I scan documents with my phone instead of a scanner?

Yes. Apps like Microsoft Lens, Adobe Scan, and Google PhotoScan use your phone camera to capture documents and convert them to PDF. They work well for quick scans and are free. Place the document on a flat surface with good lighting, open the app, and tap the camera button. The app will automatically crop and straighten the image.

What resolution should I use for documents I want to read later?

300 DPI is standard and works for almost all documents. If the text is very small or you might print the document, use 600 DPI. Anything higher than 600 DPI just makes the file bigger without making it noticeably clearer on screen.

Why is my scan blurry even though the preview looked good?

The preview is usually a small, low-resolution version. If the final scan is blurry, the document may have been slightly out of focus. Make sure the glass is clean, place the document flat against it, and close the lid gently. If you are using an automatic feeder, make sure the document is not bent or wrinkled.

Can I scan both sides of a document at once?

No — scanners can only see one side at a time. If your scanner has an automatic feeder, load all pages face-up, scan them, then flip the stack over and scan again. Your scanning software may have a "duplex" or "two-sided" option that will automatically arrange the pages in the right order.

What should I do with the paper after I scan it?

Keep the original for at least 30 days while you verify the scan is readable and complete. For important documents like tax returns or contracts, keep the original for the time period required by law — usually three to seven years depending on the document type. Once you are confident the digital copy is good, you can shred or recycle the paper.