CalcBrew

PDF Tools

Annotate PDF

Mark up a paper, review a contract or grade homework: highlight, underline, strike through, draw freehand, add notes and shapes — and save it all into the PDF.

Runs in your browser — files never leave your device.

Drop PDF file here

or click to browse · paste from clipboard · up to 100 MB

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About Annotate PDF

Reviewing documents on a laptop without Acrobat usually means a screenshot and a paint program. Real PDF annotations are searchable, removable and visible in every viewer, including the one your colleague uses.

Annotations are written as standard PDF annotation objects, so Acrobat, Preview and Chrome show them, and the recipient can reply or delete them. Choose Flatten on save if you want them fixed permanently.

How it works

  1. Drop PDF file onto the box above, click it to browse, or paste from the clipboard.
  2. Adjust the options if you need to — the defaults suit most cases.
  3. Press Convert. The work happens on your device, so speed depends on your computer or phone.
  4. Download the result.

About the format

PDF · Portable Document Format · .pdf

The fixed-layout document standard: looks the same on every device and printer, which is why forms, invoices, contracts and reports are shared as PDF.

  • A PDF can contain vector text, embedded fonts, images, form fields, annotations and digital signatures.
  • Scanned PDFs are just pictures of pages; they need OCR before the text can be searched or copied.
  • PDF is an open ISO standard (ISO 32000) since 2008.

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Frequently asked questions