Help
Is anything uploaded?
No. Every tool runs inside your browser. See how to check this yourself.
Does it work offline?
Yes. After you have used a tool once, it is stored by your browser and works with no internet connection. You can also add StarkPDF to your home screen from the menu; this is optional.
How large can files be?
On a computer, up to 500 MB. On phones, 50 MB always works and up to 200 MB when the phone has enough memory. If a file is too large for your device, you will be told before anything starts; try it on a computer, or split it first.
About signatures
“Add signature (visual)” places an image of your signature on the page. It is not a certified digital signature (such as a DSC or Aadhaar eSign in India). Many everyday documents accept visual signatures by agreement, but some cannot be signed electronically at all, such as wills, trust deeds and most powers of attorney (Schedule I of India’s IT Act). If you are unsure, ask the person who will receive the document. More in the terms of use.
“This form uses an older format”
Some government and tax forms use XFA, which browsers cannot fill. Open the form in Adobe Acrobat Reader, choose Print, pick “Microsoft Print to PDF” (Windows) or “Save as PDF” (Mac), then open the new file here.
Password-protected files
You will be asked for the password when a file needs one, and it is used only inside your browser. Files that only restrict printing or copying open without a password. Unlock never guesses passwords. Bank statements and e-Aadhaar files usually have a password described in the email or letter they came with.
On iPhone and iPad
Open StarkPDF in Safari, pick a tool, then choose your file from Files or Photos. When the result is ready, tap “Save or share” and choose “Save to Files”.
Known issues
- Edited text is saved in the closest standard font (serif, sans-serif or monospaced, in the same size, weight and colour), not the document's own font. Edited paragraphs that become longer can overlap what follows; you are warned.
- Text on scanned pages cannot be edited, because it is a picture. Redaction blacks out scanned images too, except in the CCITT, JBIG2 and JPEG 2000 formats, where you are warned that the image underneath could not be changed.
- Typing in scripts that join letters, such as Hindi, Tamil or Arabic, may not render correctly in added text yet.
- Files over 100 MB are processed in memory and may be slow on older computers. Merging needs about four and a half times the total size of the files in free memory; if a device does not have it, you are told before any work starts.
- Changing pages (rotating, inserting, moving, deleting, merging, splitting, compressing) of a digitally signed PDF removes its digital signatures, because they can no longer be valid. Filling fields, adding comments, text and signature images keeps them valid.
- Dynamic XFA forms cannot be filled; print them to PDF first (see above).
All tools
- Merge PDF — Combine PDFs and images into one file
- Organize PDF — Reorder, rotate, delete and add pages
- Delete pages — Remove pages from a PDF
- Extract pages — Make a new PDF from chosen pages
- Split PDF — Split a PDF into several files
- Rotate PDF — Turn pages the right way up
- Edit PDF — Change existing text, add text, images and shapes
- Fill and sign — Fill forms and add your signature
- Add page numbers — Number the pages of a PDF
- Watermark PDF — Stamp text across every page
- Compress PDF — Make a PDF smaller
- Compress to size — Shrink a PDF under a size limit
- Protect PDF — Add a password
- Unlock PDF — Remove a password you know
- PDF to JPG — Turn pages into images
- JPG to PDF — Turn photos into a PDF