Runs in your browser with pdf.js and pdf-lib
PDF to Grayscale Converter — gray pages, text still selectable
Turn the colors in a PDF into shades of gray for black-and-white printing or submission rules. Text, links and forms keep working, and every converted page is checked for leftover color.
- PDF files aren't uploaded to our server
- Text stays selectable
- Checked for leftover color
- Preview every page
Remove the color from a PDF, keep everything else
Add a PDF, choose how to convert it, check the pages, then download.
Drop your PDF here
or browse — one PDF, any number of pages
Your pages
Showing a preview in gray. Click a page to check it full size.
How the conversion actually works
Gray colors inside the file, not a photo of the page
Many grayscale tools take a picture of every page and throw the text away. Keep text changes the colors themselves, so the PDF stays a real document.
What Keep text changes
A PDF page is a list of drawing instructions: "use this red, draw this text, place this photo". Keep text goes through those instructions on every page you choose and replaces each color with its shade of gray. Photos and other pictures inside the page are turned gray too, and so are highlights, notes and form field colors.
After converting, each page is drawn again and checked for color that is left. Gradients and printing spot colors can't always be changed directly; a page with any of those is saved as a gray picture instead, and the result tells you which. pdf.js and pdf-lib do the work in your browser tab, so your PDF isn't uploaded to our server.
The three ways to convert
Keep text
The recommended choice for documents, forms and reports. Text stays searchable, and the file often gets smaller because gray pictures weigh less.
Gray pictures
Each page becomes one gray picture at the resolution you pick. Use it when a system must receive no color information at all.
Black and white pictures
Every pixel becomes pure black or pure white, with the cut-off worked out for each page. Crisp for text; not for photos.
A check you can trust
Every converted page is drawn again and scanned for colored pixels before the file is handed to you.
How to convert a PDF to grayscale in four steps
Keep text suits most files. Switch only if a printer or an upload rule asks for pictures.
Add your PDF
Drop a PDF onto the upload area, or click Select PDF. Every page appears in gray straight away.
Switch the pages to Original to compare at any time.
Choose how to convert
- Keep text for documents people will read, search or sign.
- Gray pictures or Black and white for scans and strict systems.
- Pages… or Pick below to leave some pages in color.
Convert
Click Convert to grayscale. The pages then show the saved file, so what you see is exactly what you'll download.
Cancel stops the work at any point.
Check and download
The result shows the new size and which pages, if any, had to be saved as pictures. Rename the file if you like, and download it.
From full color to grayscale
One colorful page, before and after.
Which option to use for your file
A starting point for common jobs. Check the converted pages before you send them.
| Job | What matters | Settings to try |
|---|---|---|
| Printing on a black-and-white printer | Predictable grays instead of the printer's own conversion. | Keep text, All pages. |
| Submission that asks for black-and-white PDFs | No color anywhere; text often still needs to be searchable. | Keep text. If the system rejects it, Gray pictures at 200 dpi. |
| Form you still need to fill in or sign | Fields and text must keep working. | Keep text only. |
| Scanned letters, faxes or signatures | Crisp black text on clean white. | Black and white pictures, 200 or 300 dpi. |
| Report where only the cover is in color | Keep the cover, gray the rest. | Pages… with 2- (page 2 to the end), Keep text. |
| Reading on an e-ink device | Text stays sharp; colors become clear grays. | Keep text. |
| Checking a design without color | Does the layout still read when color is gone? | Look at the Grayscale preview; no need to download. |
The details
What happens to each kind of color in numbers
No hidden steps: these are the rules the converter follows.
Screen colors (RGB)
Gray = 0.299 R + 0.587 G + 0.114 B, the standard luminance weights. Pure red becomes about 30% gray, pure green about 59%.
Print colors (CMYK)
Ink = 0.3 C + 0.59 M + 0.11 Y + K, capped at 100%. Black text in CMYK stays fully black.
Photos inside the page
JPEG photos are saved again as gray JPEGs at 92% quality; other pictures are saved as lossless gray. Palette pictures only have their palette changed.
Gradients and spot colors
These can't always be rewritten safely. If any color is still visible on a page after converting, that page is saved as a gray picture at the resolution you chose, and the result lists it.
The color check
Each converted page is drawn at 72 dpi and every pixel is tested; a pixel counts as colored when its red, green and blue values differ by more than 30 of 255.
Black and white
Each page gets its own cut-off between black and white, worked out from that page's tones (Otsu's method). Pictures are saved at 90% JPEG quality.
When the converted file isn't what you expected
Identify the problem, then use the matching fix.
Chart colors look the same
Different colors can have nearly the same brightness, for example a medium red and a medium green.
Change the chart's colors or add labels in the source document, then convert again.
Text on one page can't be selected
That page had a gradient or spot color, so it was saved as a picture to remove every trace of color. The result names these pages.
Leave that page out with Pages… if it may stay in color, or accept the picture version.
Black and white loses parts of a photo
Black and white keeps only two tones, which suits text but not pictures.
Use Keep text or Gray pictures for pages with photos.
The file got bigger
Pages saved as pictures usually weigh more than text and drawings.
Use Keep text, choose 150 dpi, or run the result through Compress PDF.
"Pages to convert" shows an error
A number is past the last page, a range is reversed, or there's a typo.
Follow the message under the box. Use forms like 1-3, 7 or 10- for "to the end".
It takes a while on a big file
Every page is converted and then drawn again for the color check, on your own device.
Keep the tab open; the progress bar counts the pages. Close other tabs if memory is low.
A password-protected PDF won't open
Encrypted PDFs can't be rewritten by the in-browser PDF libraries.
Remove the password with Unlock PDF, then add the unlocked copy.
A clean gray file on the first try
A working order that avoids a second round.
Start with Keep text
It keeps the PDF searchable and usually smaller. Switch to pictures only when a system insists.
Look at charts and color-coded text
Red and green can turn into the same gray. Open those pages full size before you send the file.
Use Black and white only for text scans
Signatures, faxes and typed letters come out crisp. Photos and shaded charts don't.
Leave the cover in color if you can
Pages… lets you keep a color cover or chart pages while the rest goes gray for printing.
Read the result note
It names any page that had to become a picture, so you know where text is no longer selectable.
Keep the original
Color can't be brought back from a gray file. Keep the color PDF as your master copy.
Common questions about grayscale PDFs
If something's not covered here, the troubleshooting section above likely has it.
Does this tool upload my PDF to a server?
No. The conversion runs in your browser with pdf.js and pdf-lib. Your PDF is read on your device and is not uploaded to the AllInOneTools server.
Will my text still be selectable after converting?
Yes, with Keep text. It changes the colors inside the PDF instead of taking a picture of each page, so text, links, bookmarks and form fields keep working. Gray pictures and Black and white turn each page into a picture, so text can't be selected there.
How do I know no color is left?
After converting, every page you chose is drawn again and each pixel is checked. If a page still shows color, for example from a gradient or a printing spot color, that page is saved as a gray picture instead, and the result tells you which pages that happened to.
Can I keep some pages in color?
Yes. Choose Pages… and type numbers or ranges such as 2-, which means page 2 to the end, or choose Pick below and tap Convert on the pages you want. Every other page keeps its colors and is not changed.
Will the file get smaller?
With Keep text it often does, because gray photos need less data than color ones. Gray pictures and Black and white replace each page with a picture, which can make a text document bigger; the result shows the new size.
What is the difference between grayscale and black and white?
Grayscale keeps every shade from black to white, so photos and charts still show detail. Black and white keeps only pure black and pure white, which is crisp for text, faxes and signatures but loses detail in photos.
Can I turn a grayscale PDF back into color?
No. Once colors are replaced with grays, the original colors can't be worked out again. Keep your color PDF; this tool never changes it and saves the gray version as a new file.
Build notes
The write-up on grayscale PDFs in the browser
I wrote a tutorial on building a browser-based PDF to grayscale converter with JavaScript, drawing each page on a canvas, the approach the Gray pictures option also uses.
How to Build a Browser-Based PDF to Grayscale Converter Using JavaScript
Renders each page with pdf.js, turns every pixel gray with a luminance formula on a canvas, and builds the new PDF with pdf-lib.