Scanner Test

This scanner test checks what your scanner actually captures, not what its settings claim. Print the scanner test page, scan it, and open the scan in the tool above. The page finds the four round marks on the chart and measures the real resolution in both directions, how far the page is tilted, how many gray steps survive, whether gray comes out tinted, how much fine detail is left, and whether lines run through the blank band. It works with flatbed scanners, document feeders and all-in-one printers from HP, Canon, Epson, Brother and every other brand, on Windows, Mac, ChromeOS and phones, and the scan never leaves your device.

How to test your scanner

1. Press Print chart, or download the PDF for US Letter or A4. In the print window choose 100% or Actual size.
2. Check the printed chart with a real ruler. The millimeter ruler should measure 100 mm from 0 to 100. If it does not, print again, because a scaled chart gives a wrong resolution reading.
3. Scan the chart in color at 300 dpi or more, with automatic cropping turned off so the four round marks stay in the picture. To test the document feeder, scan the chart through the feeder too.
4. Save the scan as JPEG or PNG, then press Open scan or drop the file on the picture.
5. Read the readouts and the list of findings. Each finding names the likely cause and the fix.
6. Press Copy results to keep a record or send it to the maker's support.

What the results mean

The detail table shows how much contrast survives in each group of fine lines. A 300 dpi scan can show up to about 5 line pairs per mm and a 600 dpi scan about 10, so finer groups are marked n/a. If the scan stays sharp well below that, the scanner or its settings are blurring the page.

Lines or streaks on every scan

A line that runs down the whole page, in the direction the paper moves, comes from something stuck on the glass where the sensor reads.

• Document feeder scans only. The feeder reads the page through a narrow glass strip, usually at the left side of the main glass on HP, Canon, Epson and Brother all-in-ones. Spray glass cleaner on a soft cloth, never on the glass, and wipe the strip and the white strip on the underside of the lid above it. Correction fluid and label glue are the usual culprits.
• Flatbed scans too. Clean the whole glass and the white pad on the lid. A line that moves when you move the page is on the page, not the scanner.
• Lines that survive cleaning. Dirt can sit on the inside of the glass or on the sensor. On an all-in-one that is a job for service.
• Lines across the page point to the scan head stuttering or the lamp flickering. Plug the scanner straight into the computer or a wall socket, update the driver and try again.

Blurry or soft scans

Most slim scanners and all-in-ones use a contact image sensor, which is only sharp right at the glass. Anything that lifts the page blurs it.

• Close the lid fully, and press thick books flat with your hand on the lid.
• Clean the glass. A film of fingerprints softens every scan.
• Turn off noise reduction, descreen and "smooth" options unless you scan printed photos from magazines.
• Save as PNG, TIFF or high quality JPEG. Low quality JPEG blurs fine text into blocks.
• If detail is lost in one direction only, the page moved while it was read. On a feeder that means worn rollers.

The detail groups depend on your printer too. Look at the finest groups on paper with a magnifier first. If your printer could not print them cleanly, the scan cannot show them, and the printer test page helps you check the print quality.

Colors look wrong or the scan has a tint

The gray steps on the chart are printed with black ink, so any tint in the scan comes from the scanner side.

• Warm or yellow tint. The lamp was cold. Let the scanner warm up for a minute after switching on and scan again.
• Tint that changes from scan to scan. Turn off automatic color correction, "color restoration" and photo enhancement in the scan software.
• A steady tint. Run the calibration in the scanner utility if your model has one, and check the scanner profile is not switched off. A tint that stays after that points to an aging lamp.

To judge colors by eye you also need a trustworthy screen, which the monitor color test helps you check. For printed color problems on an all-in-one, a color test page tells you whether the printer or the scanner is at fault.

Scans too dark or too light

If white paper comes out gray, raise the brightness or exposure. If the lightest gray step merges with the paper, highlights are clipped, which makes pencil and faint stamps vanish: lower the brightness or contrast, and turn off "background removal" and "text enhancement". If the 90% and 100% steps merge, shadows are clipped, so lower the contrast.

Crooked scans from the document feeder

A tilt over half a degree usually comes from the paper guides. Slide them in until they touch both edges of the stack, fan the pages before loading them, and do not overfill the tray. If one side of the page always leads, the rollers are worn unevenly. Most scan apps can also straighten pages automatically with an option called deskew or auto straighten.

Wrong size or a stretched scan

When the real resolution differs from the file's stored value by more than 2%, the picture was resized somewhere: by printing the chart scaled, or by a fit, zoom or output size option in the scan app. When the page is squashed or stretched from top to bottom only, the paper slipped in the feeder, or on a flatbed the carriage moved unevenly. Clean the rollers with a lint free cloth and a little water and replace them if they look shiny or cracked.

Best scan settings

On Windows, the Windows Scan app and the scanner maker's app both offer these settings. On a Mac, use Image Capture and press Show Details. If the scanner does not appear at all, start with the usb not recognized steps, and for all-in-ones that also refuse to print, the printer not printing guide covers drivers and connections.

Testing a barcode scanner instead

This page is for document scanners. To check a handheld scanner that reads barcodes or QR codes, use the barcode scanner test, which shows exactly what the scanner types and how fast.

What this scanner tester cannot measure

The chart is printed on your own printer, so it is not a calibrated color target. It shows tints, clipping and faults clearly, but it cannot profile a scanner for exact color matching, which needs a professional IT8 target and profiling software. The resolution reading is accurate to about 0.2% when the chart was printed at 100%. The page cannot test scan speed, double sided scanning or how reliably the feeder picks up paper, and it cannot open PDF scans, or TIFF files outside Safari.

Scanner test questions