How to convert a PDF to grayscale: a step-by-step guide

更新日期：2026年10月2日

本指南尚未提供繁體中文版，因此以英文顯示。工具本身支援繁體中文。

Convert PDF to grayscale turns every colour in a PDF into its grey - for a black-and-white printer, a handout, an archive that shouldn't carry colour. The text and drawings stay what they are, sharp and selectable; only their colour changes. Pictures and gradients turn grey too. It all happens in your browser; nothing is uploaded.

免註冊即可免費試用：你的檔案不會離開你的裝置。

開啟PDF 轉灰階

重點摘要

Drop your PDFs on the page, or press Add files.
Look at the pages: the preview shows them in grey.
Press Convert to grayscale.
The grey PDF is saved to your device straight away.

Add the files

Drop the PDFs anywhere on the page, or press Add files. The pages of the selected file appear in grey right away - the screen's version of the result.

Convert PDF to grayscale with three files in the list: the brochure's photo pages already shown in grey

What changes

Text and drawings keep their shape and stay selectable; each colour becomes the grey of the same brightness.
Pictures are turned grey - photos, logos, scans.
Gradients and colour fills get grey colours.
Comments, highlights and form fields turn grey as well.

Nothing is turned into a picture of the page, so nothing gets blurry - and a file with many photos often gets smaller, as a grey picture needs less room than a colour one.

Convert and save

Press Convert to grayscale. The grey PDF is saved to your device at once - several files together as a ZIP - and the file list says what was converted in each: so many images, so many gradients.

After converting: the file list shows 4 images converted, the button says Saved

A rare element that can't be converted - a JPEG 2000 picture, for instance - stays in colour, and the result says how many there were.

Limits

Without an account, and with a free one, you can convert two files in a run, each up to 15 MB. With Pro there is no limit on the number or the size. The tool has no settings to choose: every file is converted the same way.

What next?

Smaller still for e-mail? Compress PDF.
Several pages on one sheet to save paper? N-up (Multiple Pages per Sheet).
Pages as pictures instead? PDF to Image.

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