Help & FAQ

This page explains how PDFCuibu works, what to do when something fails, and how to get fast support. We try to keep the tools simple: upload, choose options, download. If you get stuck, the answers below cover the most common cases.

Quick start (recommended workflow)

Pick the right tool from All tools.
Upload your file(s) and wait for the processing to finish.
Download the result. If the link expires, just run the tool again.
If you see an error, copy the tool URL and the exact error text, then use the Contact form.

Uploads & limits

Different tools accept different input types. Most tools accept PDF. Some tools accept images (JPG/PNG/WEBP) to build a PDF. Limits are influenced by the web server configuration (upload size, timeouts) and by how heavy the processing is (very large scanned PDFs can be slow).

File size: If upload fails or times out, try compressing first or splitting the PDF into parts.
Multiple files: Merge PDF and Images-to-PDF require selecting multiple files in the uploader.
Page ranges: For tools that accept ranges, use formats like 1-3,7,10-12.

Privacy & storage

These tools run on a server to produce your output, which means your files are uploaded and processed remotely. Files are stored temporarily for processing and deleted on scheduled cleanup (typically within 12 hours). Still, do not upload sensitive documents unless you are comfortable using an online service. If you need maximum confidentiality, consider running offline tools on your own machine.

Quality and output expectations

PDF conversions are not always perfect because PDFs can contain scanned pages, embedded fonts, vector drawings, transparency, forms, and encryption. If quality matters (printing, legal documents, archiving), test with a small sample first.

Compression reduces file size by re-encoding images and optimizing content. Strong compression can reduce readability on scanned documents.
Image extraction pulls embedded images; scanned PDFs may contain one large image per page.
Text extraction depends on whether the PDF actually contains selectable text. If it’s a scan, you may need OCR.

FAQ (20+ questions)

1) Why did my upload fail?: Most failures are due to file size limits, slow connections, or timeouts on very large PDFs. Try a smaller file, compress it, or split it into parts and process them separately.
2) What file types do you support?: Most tools accept PDF. Image-to-PDF accepts common formats like JPG/JPEG, PNG, and WEBP. Each tool page lists the accepted types.
3) Is there a maximum file size?: Yes, but it depends on server configuration. If you hit limits, compress first, remove metadata, or split the file before uploading.
4) How do I merge multiple PDFs?: Open Merge PDF, select multiple files (Ctrl/Shift selection on desktop), then run the tool. If you need a specific order, rename files or re-upload in the desired order.
5) How do I split a PDF by page ranges?: Use Split PDF and enter ranges like 1-3,5,9-12. If you need every page as separate files, split into a wide range and re-split outputs as needed.
6) Why is the compressed PDF blurry?: Compression often downscales or re-encodes images. Choose a lighter level (or avoid compressing a scanned document too aggressively). If the PDF is text-based, compression usually keeps it sharp.
7) The output file is larger than the input. Why?: Some PDFs are already optimized. Re-encoding can sometimes increase size. Try a different level or a different workflow (remove metadata, split, then compress).
8) Why can’t you extract text from my PDF?: If the PDF is a scan (images), there is no real text layer to extract. You need OCR (optical character recognition). We may add OCR tools later.
9) What does “Remove metadata” do?: It removes document properties like title/author and can strip some embedded metadata. It does not guarantee anonymization for all possible embedded data, but it helps reduce obvious metadata.
10) My PDF is password protected. What can I do?: If you know the password, use Unlock PDF, then run the desired tool. If you don’t know the password, we cannot remove encryption.
11) How do I protect a PDF with a password?: Use Protect PDF and choose a strong password. Remember that password-protected PDFs can become harder to process in other tools until you unlock them again.
12) Why do extracted images look low quality?: Extraction returns images embedded in the PDF. If the PDF was generated from compressed images, the originals are already low quality. For best results, export from the source document when possible.
13) Why do pages look rotated after conversion?: Some PDFs use rotation flags. Use Rotate PDF to normalize orientation. If a tool produces rotated output, rotating the input first usually fixes it.
14) Can I rearrange pages?: Yes. Use Rearrange Pages and provide the new order (for example: 3,1,2,4). Double-check the numbering before running.
15) What should I include when reporting a bug?: Please include the tool URL, approximate file size, file type, steps to reproduce, and the exact error text. If possible, mention your browser and OS.
16) Why does the tool say “error” but I don’t see details?: Sometimes the server returns a generic error for safety. If it repeats, send us the time it happened and the tool URL via the Contact form so we can check logs.
17) Do you keep my files?: Files are stored temporarily for processing and deleted on scheduled cleanup (typically within 12 hours). Avoid sensitive documents and re-run the tool if a link expires.
18) Can I use PDFCuibu on mobile?: Yes. The UI is responsive. For very large files, desktop browsers may be more reliable due to memory and upload stability.
19) Why does processing take a long time?: Large scanned PDFs require heavy image work. Conversions like PDF-to-images or OCR-like operations (if added) can be slow. Try smaller files or fewer pages.
20) The download link doesn’t work.: It may have expired or the file was cleaned up. Re-run the tool. If it happens repeatedly, contact support with the tool URL and time of the attempt.
21) How do I reduce file size without losing too much quality?: Start with a medium level, then compare. For scanned docs, try grayscale before compression and avoid very aggressive settings.
22) Can I process many files automatically?: Right now the site is optimized for interactive use. If you need automation or API access, contact us and describe your workflow.

Still need help?

Use the Contact form. We reply by email. Include: tool URL, file size, file type, and error text.