Add Annotations

Highlight, underline, freehand.

100% private Runs locally No sign-up

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Heavy libraries load on demand so the page shell stays fast.

About Add Annotations

Add Annotations (annotate pdf) is a free pdf tools tool on Toolncy. Highlight, underline, freehand. Unlike cloud converters, annotate pdf runs locally with WebAssembly and browser APIs — your files never leave this device. No account, no upload queue, and no watermarks. Browse 34 tools in PDF Tools when you need a related step.

How to use Add Annotations

1Open Add Annotations on Toolncy — no install or sign-up.
2Drop your PDF into Add Annotations, or click to select files stored on this device.
3Set annotate pdf options for your document, then run processing in the browser.
4Download the updated PDF from Add Annotations. Source pages were never uploaded.

Frequently asked questions

Is Add Annotations free to use?

Yes. Add Annotations on Toolncy is free with no tiers, trials, or sign-up. Use annotate pdf as often as you need.

Does Add Annotations upload my files?

No. Add Annotations processes everything locally in your browser. Toolncy never receives the files you open for annotate pdf.

Is Add Annotations safe for confidential work?

Yes for architecture: nothing is uploaded. Still use a trusted device — local malware can read browser memory like any app.

Does Add Annotations work on phones?

Yes on modern mobile browsers. Heavy pdf tools jobs may be slower on older phones because annotate pdf runs on-device.

Will Add Annotations change PDF quality?

Add Annotations preserves page content unless you choose a compress/optimize mode. Vector text and embedded fonts stay intact when the operation is structural.

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About Add Annotations

How to use Add Annotations

1Open Add Annotations on Toolncy — no install or sign-up.

2Drop your PDF into Add Annotations, or click to select files stored on this device.

3Set annotate pdf options for your document, then run processing in the browser.

4Download the updated PDF from Add Annotations. Source pages were never uploaded.

Frequently asked questions

Is Add Annotations free to use?

Yes. Add Annotations on Toolncy is free with no tiers, trials, or sign-up. Use annotate pdf as often as you need.

Does Add Annotations upload my files?

No. Add Annotations processes everything locally in your browser. Toolncy never receives the files you open for annotate pdf.

Is Add Annotations safe for confidential work?

Yes for architecture: nothing is uploaded. Still use a trusted device — local malware can read browser memory like any app.

Does Add Annotations work on phones?

Yes on modern mobile browsers. Heavy pdf tools jobs may be slower on older phones because annotate pdf runs on-device.

Will Add Annotations change PDF quality?

Add Annotations preserves page content unless you choose a compress/optimize mode. Vector text and embedded fonts stay intact when the operation is structural.