# Convert a PDF to grayscale

Make a gray copy of a PDF file with `sumatrapdf-tool recolor`, or only view pages in gray in SumatraPDF with **Toggle Grayscale**.

**Available in [pre-release 3.7](https://www.sumatrapdfreader.org/prerelease)**

**To make a gray PDF file, run `sumatrapdf-tool recolor -c gray -o gray.pdf color.pdf`.** At a glance:

- **Gray PDF file:** `sumatrapdf-tool recolor` rewrites the colors of text, graphics and images as shades of gray.
- **View in gray:** **Toggle Grayscale** (`CmdToggleGrayscale`) shows pages in gray on screen. The file doesn't change.
- **Print in gray:** `monochrome` in `-print-settings`, or print the gray PDF made by `recolor`.

## Make a grayscale PDF file

Use `sumatrapdf-tool recolor`, or [SumatraPDF.exe recolor](Tools.md) with the same arguments:

```
sumatrapdf-tool recolor -c gray -o report-gray.pdf report.pdf
```

- Every page is converted: text, vector graphics and images.
- `-c gray` is the default, so `sumatrapdf-tool recolor -o report-gray.pdf report.pdf` does the same.
- Without `-o` the result is written to `out.pdf` in the current folder.
- Add `-r` to also remove output intents (color profiles for print production).
- The command prints nothing when it succeeds.

Open the new file in SumatraPDF to check it, or render a page to an image: `sumatrapdf-tool draw -o check.png report-gray.pdf 1`.

`recolor` can also convert to other color spaces: `-c rgb` or `-c cmyk`.

Note: colors of similar brightness become similar grays. In a test, red text, a blue box and green text came out as 47%, 35% and 52% gray, so a chart that relies on color alone can become hard to read.

## View pages in grayscale in SumatraPDF

`Ctrl + K`, then `Toggle Grayscale` in [Command Palette](Command-Palette.md). Run it again to go back to color.

- It isn't in any menu. To give it a shortcut, [customize a keyboard shortcut](Customize-keyboard-shortcuts.md) for `CmdToggleGrayscale`.
- It changes only how pages look on screen. The file isn't modified and printing isn't affected.
- It applies to all documents and is remembered after restart: it's saved as `Grayscale` in `FixedPageUI` in [advanced settings](Advanced-options-settings.md). You can also set it there:

```
FixedPageUI [
    Grayscale = true
]
```

- Only the page image is gray. Text selection, search highlights and other things drawn on top of the page keep their colors.

## Print in grayscale

**Toggle Grayscale** doesn't change the printout. Instead:

- From the command line, add `monochrome` to `-print-settings`. It asks the printer driver to print in black and white:

```
SumatraPDF.exe -print-to "Office Printer" -print-settings "monochrome" report.pdf
```

- In the print dialog (`Ctrl + P`), choose grayscale or black and white in the printer's own options. The option's name depends on the printer driver.
- Or print the gray PDF made with `recolor`. That works with every printer.

See [Printing](Printing.md) for all print options.

## Tips

- Use `recolor` before sending a document to a black-and-white printer or copier, to see how it will look.
- Use **Toggle Grayscale** to read a colorful document with less distraction, without making a copy.
- To make gray images of pages instead of a PDF, use `sumatrapdf-tool convert -o page%d.png -O colorspace=gray report.pdf` (see [Convert PDF to images](Convert-PDF-to-images.md)).
- To convert a whole folder, see [Process many PDFs at once](Batch-process-PDFs.md).

## See also

- [sumatrapdf-tool recolor](Tool-recolor.md) — all options
- [Printing](Printing.md) — `-print-settings` and the print dialog
- [Command Palette](Command-Palette.md) — run **Toggle Grayscale**
- [All cmd-line tools](Tools.md)