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

更新日: 2026年10月2日

このガイドはまだ日本語に対応していないため、英語で表示しています。ツール自体は日本語で使えます。

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.

登録不要で無料でお試しいただけます。ファイルが端末の外に出ることはありません。

概要

  1. Drop your PDFs on the page, or press Add files.
  2. Look at the pages: the preview shows them in grey.
  3. Press Convert to grayscale.
  4. 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?

さっそく試してみましょう

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