Is ThinPDF really free?

Yes, completely. All tools on ThinPDF are 100% free to use with no hidden fees, premium tiers, or feature limitations. We don't require account creation or payment information. The project is supported by voluntary donations from users who find the tools helpful.

Do I need to create an account?

No. ThinPDF works without any registration or sign-up. Simply visit the tool you need, upload your file, and get your result. No email address, username, or password required.

What devices and browsers are supported?

ThinPDF works on any device with a modern web browser, including desktop computers, laptops, tablets, and smartphones. We support Chrome, Firefox, Safari, Edge, and other modern browsers. No software installation is needed.

What is the maximum file size I can upload?

Individual files can be up to 100MB in size. For the Merge PDFs tool, the combined total of all files can be up to 500MB. If your file exceeds these limits, consider splitting it into smaller parts first.

How many times can I use the tools?

There are no usage limits. You can compress, merge, convert, protect, and unlock as many PDFs as you need. We don't impose daily caps or throttle frequent users.

Are my files safe?

Yes. Your files are uploaded over a secure HTTPS connection, processed on our servers, and automatically deleted within 10 minutes. We don't store, read, or share your documents. No human ever sees your files — the entire process is automated.

Do you store my files or personal data?

No. We don't collect personal information (names, emails, IP addresses) and we don't keep your files after processing. Both the original and processed files are permanently deleted within 10 minutes. Read our full Privacy Policy for details.

Can I use ThinPDF for confidential documents?

While we take security seriously with HTTPS encryption and automatic file deletion, we recommend using our Protect PDF tool to add password encryption for highly sensitive documents. For documents subject to strict regulatory compliance (HIPAA, classified materials), consult your organization's security policy about using online tools.

What encryption does the Protect PDF tool use?

Our Protect PDF tool uses AES-256 encryption, which is the same standard used by governments and financial institutions. This is currently the strongest widely-available encryption standard for PDF documents.

How much can I reduce my PDF file size?

Results vary depending on the PDF content. Files with large images typically see the biggest reductions — up to 90% smaller. Text-heavy documents or already-optimized PDFs may see smaller reductions (10-30%). The tool always shows you the exact size reduction achieved.

What's the difference between Regular and Smallest Size compression?

Regular compression provides a good balance between file size reduction and quality. It's recommended for most use cases like email attachments and web uploads. Smallest Size applies maximum compression for the smallest possible file, which may slightly reduce image quality. Try Regular first — if the file is still too large, use Smallest Size.

Will compression affect the quality of my PDF?

Regular compression preserves quality that is visually indistinguishable from the original for most documents. Text, vector graphics, and page layout remain unchanged. Only embedded images are optimized. With Smallest Size compression, images may have slightly visible quality reduction, but text and layout remain intact.

Can I compress a password-protected PDF?

No. Password-protected PDFs must be unlocked first before they can be compressed. Use our Unlock PDF tool to remove the password (you'll need the correct password), then compress the unlocked file.

How many PDFs can I merge at once?

You can merge as many PDF files as you need, as long as the combined total size stays under 500MB. There is no hard limit on the number of individual files.

Can I reorder the pages before merging?

Yes. After uploading your files, you can drag and drop them to arrange the order before merging. The files will be combined in the order you specify.

Will my formatting be preserved when converting to Word?

We do our best to preserve formatting, including text styles, tables, images, and layout. Simple documents convert with high fidelity. Complex layouts with multiple columns, custom fonts, or intricate designs may require minor adjustments after conversion.

Can I convert scanned PDFs (image-based) to Word?

Our converter works best with text-based PDFs (documents created from Word, web pages, or other digital sources). Scanned PDFs (which are essentially images) will convert, but the text may not be editable since OCR (Optical Character Recognition) is not currently supported.

What image formats can I download?

You can download pages as PNG or JPG. PNG is lossless and best for documents with text, diagrams, or sharp lines. JPG produces smaller files and is better suited for photo-heavy pages where a slight quality reduction is acceptable.

What resolution are the output images?

Pages are rendered at 200 DPI (dots per inch). This produces sharp, high-quality images suitable for screen viewing, web embedding, and presentation slides. A standard A4 page at 200 DPI is approximately 1654 × 2339 pixels.

Can I convert only specific pages instead of the whole PDF?

Yes. The page range field lets you enter a range like 1-5 or a single page like 3. Leave it blank to convert all pages. Targeting specific pages is faster for large documents when you only need a few pages.

How are the converted images delivered?

All converted pages are packaged into a single ZIP file for download. Each image inside is named with the original PDF filename and the page number (e.g. report_page_1.png), so they are easy to identify and extract.

What image formats are supported?

The tool accepts JPG, PNG, WEBP, BMP, TIFF/TIF, and GIF. GIF files are converted using the first frame. Most images from phones, scanners, and the web are covered. Each image file can be up to 50MB, and the total upload across all files can be up to 500MB.

Is there a limit on how many images I can combine?

There is no hard limit on the number of images. You can combine as many as you need, as long as the total size of all images stays under 500MB. Very large batches may take longer to process.

Can I control the order the images appear in the PDF?

Yes. After uploading, your images are shown in a list with numbered badges. Drag and drop any row to change its position. The final PDF will follow the order shown in the list at the time you click Create PDF.

What page sizes are available?

Original uses each image's natural dimensions as the page size — best for photo albums and portfolios. A4 (210 × 297 mm) fits images to the international standard page — best for formal documents. Letter (8.5 × 11 in) targets the US standard — best for reports and submissions in North America. Images are always scaled proportionally; nothing is cropped.

My download link expired. Can I recover my file?

Unfortunately, no. Files are permanently deleted after 10 minutes for your privacy. You'll need to upload and process your file again. We recommend downloading your result immediately after processing.

I'm getting an error when uploading my file. What should I do?

Common causes include: the file isn't a valid PDF, the file exceeds the 100MB size limit, or the PDF is password-protected. Make sure your file has a .pdf extension and is within the size limit. If the PDF is locked, use our Unlock PDF tool first. If the problem persists, try a different browser or contact us.

The compressed file is larger than the original. Why?

This can happen with PDFs that are already highly optimized or very small. If the original file is already compressed or contains mostly text with minimal images, further compression may not reduce the size. In rare cases, the compression metadata can make the output marginally larger.

Processing seems stuck. What should I do?

Large files (over 50MB) may take longer to process. If the progress bar hasn't moved for more than 2 minutes, try refreshing the page and uploading again. If the issue persists, the file may be corrupted or in an unsupported format. Try with a different PDF to confirm.

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