How is this different from other online PDF tools?

Most online PDF tools send your files to a remote server for processing. This tool processes everything locally in your browser using client-side JavaScript. Your files are never transmitted to any server, which means your document content stays entirely under your control.

Are my PDF files uploaded?

No. Your files are read directly by your browser. Your files are never transmitted over the network. The tool works entirely within the browser tab you have open.

Can I verify that files are not uploaded?

Yes. Open your browser's developer tools (F12), go to the Network tab, and watch for any outgoing requests while using the tool. You will see no file data leave your browser. The site may record an anonymous page-view count, which never includes your files and can be disabled.

Does this tool work offline?

Yes, once the page has loaded the tool processes your files entirely in your browser; tool functionality needs no network connection. You can disconnect from the internet and continue using it.

What happens when I refresh the page?

Because nothing is stored on a server, refreshing the page clears your current session. Any files you had selected will need to be selected again.

Does this tool store my files?

No. Files are held in browser memory only for as long as the page is open. Closing or refreshing the page discards them. Nothing is written to disk by the tool, and nothing is sent to a server.

Can this tool unlock password-protected PDFs?

No. This tool does not attempt to remove or bypass PDF password protection. If you know the password, the Unlock PDF tool on this site can remove it locally; then this tool can process the file.

What technologies does this tool use?

This tool uses pdf.js (Mozilla's client-side PDF engine) to render pages in a Web Worker, the Canvas API to desaturate them, and pdf-lib to rebuild the PDF — all within your browser.

Does this tool use WebAssembly?

No. pdf.js is a plain JavaScript library — it does not use WebAssembly. All rendering and desaturation happens in client-side JavaScript within your browser.

How do I convert my PDF to grayscale here?

Pick a PDF from your device with the file picker, then press Convert. Each page is desaturated locally in your browser and, when it finishes, a Save button appears so you can download the grayscale version — nothing ever leaves your device.

Why is the text in my converted PDF no longer selectable or searchable?

To desaturate colours reliably, each page is rendered onto a canvas, turned grayscale, and saved back as a JPEG image, so the page becomes a picture rather than live text. This makes the result ideal for black-and-white printing or archiving, but copy, search, and text selection will no longer work on the output.

Why did my grayscale PDF end up larger than the original?

Because every page is replaced by a rasterised JPEG image, a mostly text document can grow in size, since crisp vector text is heavier to store as a picture. Colour-heavy scans usually shrink, while plain text-only files may increase; the tool shows the before-and-after size after conversion.

Does the Grayscale PDF tool cost anything to use?

The Grayscale PDF tool is completely free — no account, no sign-up, and no cap on how many PDFs you convert, and it always will be. Every page of your PDF is desaturated to black-and-white directly inside your browser, so your files never leave your device and are never sent to any server.

Convert a PDF to Grayscale Privately — Save Ink, Keep Files on Your Device

Select a PDF and download a grayscale version — every page is desaturated locally in your browser, with no upload.

Quick answer

What it does: Select a PDF and download a grayscale version — every page is desaturated locally in your browser, with no upload.
Free?: Yes — 100% free, no account or sign-up.
Files uploaded?: No — everything is processed in your browser.
Works offline?: Yes — once the page has loaded.
Best for: A finance team converts a colour annual report to grayscale before printing on a mono laser printer to save toner.
Good to know: Grayscale conversion rasterises each page, so it is lossy: selectable and searchable text is removed and pages become images.

How it works

Select a PDF file from your device using the file picker.
The file is read into browser memory — no data leaves your browser.
pdf.js renders each page to a canvas, which is desaturated to grayscale using the Canvas API.
pdf-lib reassembles the grayscale pages into a new PDF, keeping each page's original dimensions.
The grayscale PDF is offered as a download directly from your browser.

When to use this tool

A finance team converts a colour annual report to grayscale before printing on a mono laser printer to save toner.
An archivist strips colour from scanned records to reduce file size for long-term cold storage.
A student turns a colourful slide deck into a print-friendly grayscale handout.
Grayscale conversion rasterises every page: selectable and searchable text is removed and pages become images in the output.

Frequently asked questions

How is this different from other online PDF tools?: Most online PDF tools send your files to a remote server for processing. This tool processes everything locally in your browser using client-side JavaScript. Your files are never transmitted to any server, which means your document content stays entirely under your control.
Are my PDF files uploaded?: No. Your files are read directly by your browser. Your files are never transmitted over the network. The tool works entirely within the browser tab you have open.
Can I verify that files are not uploaded?: Yes. Open your browser's developer tools (F12), go to the Network tab, and watch for any outgoing requests while using the tool. You will see no file data leave your browser. The site may record an anonymous page-view count, which never includes your files and can be disabled.
Does this tool work offline?: Yes, once the page has loaded the tool processes your files entirely in your browser; tool functionality needs no network connection. You can disconnect from the internet and continue using it.
What happens when I refresh the page?: Because nothing is stored on a server, refreshing the page clears your current session. Any files you had selected will need to be selected again.
Does this tool store my files?: No. Files are held in browser memory only for as long as the page is open. Closing or refreshing the page discards them. Nothing is written to disk by the tool, and nothing is sent to a server.
Can this tool unlock password-protected PDFs?: No. This tool does not attempt to remove or bypass PDF password protection. If you know the password, the Unlock PDF tool on this site can remove it locally; then this tool can process the file.
What technologies does this tool use?: This tool uses pdf.js (Mozilla's client-side PDF engine) to render pages in a Web Worker, the Canvas API to desaturate them, and pdf-lib to rebuild the PDF — all within your browser.
Does this tool use WebAssembly?: No. pdf.js is a plain JavaScript library — it does not use WebAssembly. All rendering and desaturation happens in client-side JavaScript within your browser.
How do I convert my PDF to grayscale here?: Pick a PDF from your device with the file picker, then press Convert. Each page is desaturated locally in your browser and, when it finishes, a Save button appears so you can download the grayscale version — nothing ever leaves your device.
Why is the text in my converted PDF no longer selectable or searchable?: To desaturate colours reliably, each page is rendered onto a canvas, turned grayscale, and saved back as a JPEG image, so the page becomes a picture rather than live text. This makes the result ideal for black-and-white printing or archiving, but copy, search, and text selection will no longer work on the output.
Why did my grayscale PDF end up larger than the original?: Because every page is replaced by a rasterised JPEG image, a mostly text document can grow in size, since crisp vector text is heavier to store as a picture. Colour-heavy scans usually shrink, while plain text-only files may increase; the tool shows the before-and-after size after conversion.
Does the Grayscale PDF tool cost anything to use?: The Grayscale PDF tool is completely free — no account, no sign-up, and no cap on how many PDFs you convert, and it always will be. Every page of your PDF is desaturated to black-and-white directly inside your browser, so your files never leave your device and are never sent to any server.