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FAQ

HELP DESK / PDF SEALBOX

PDF questions, answered.

From choosing a tool to checking an export, check the answer here, then return to the tool.

FAQ / 0138 questions, 7 topicsCovers all six tools plus files, privacy and responsible use.

Questions are organized by all six tools, with shared guidance for files, privacy, compatibility and responsible use. Choose a topic to jump to the answer, then open the matching workflow.

01

TOPIC

Stamp PDF

Add regular stamps, signature images or cross-page seals, then review every page before export.

Open Stamp PDF

What is the difference between a regular stamp and a cross-page seal?

A regular stamp places a complete mark inside each page, while a cross-page seal splits one mark across page edges so people can check continuity in a multi-page file. Both are visible page marks, not digital signatures or tamper-proof evidence.

When should I use a preset stamp or a custom image?

Preset stamps work well for common statuses such as PAID, APPROVED, DRAFT or COPY. Custom images are better for company seals, department marks or signature images. Only upload images and use seals that you are authorised to handle.

Can I stamp only selected pages?

Yes. Use the page-range controls for all pages, a defined range, odd or even pages, or an exclusion rule. Then check the first page, last page, landscape pages and dense pages in the preview.

Why is my stamp blurry, white-backed or covering text?

A white background usually comes from an opaque JPG or an unprepared image. Blur usually comes from low resolution. Use a clean transparent PNG and adjust scale, opacity and placement while checking the preview.

Is a PDF stamp the same as a digital signature?

No. A stamp or signature image is visible page artwork. It does not verify signer identity, detect tampering or provide a certificate. Use a compliant signing platform when formal electronic signatures are required.

02

TOPIC

Add Page Numbers

Set the page range, starting number, template, position, margins and appearance.

Open Page Numbers

Can I add numbers to only part of a PDF?

Yes. Set the page range, then check the first and last numbered pages in the preview. If the cover, contents page or appendices should stay unnumbered, verify that they are excluded before export.

What is the difference between a preset and a custom number template?

Presets cover common page-number styles. Custom templates let you use placeholders such as page and pages to create a format like Page 1 of 12. Always check the rendered result after changing the template.

Where can page numbers be placed?

The tool provides six conventional header and footer positions: left, center and right at the top or bottom. Horizontal and vertical margins help keep the number away from text, binding or crop areas.

How do I start the body at page 1 after a cover?

Combine the page range with the starting number. Exclude the cover, set the first body page as the start of the range, and use 1 as the starting number. Review the source order and displayed number together.

What should I do if Chinese page numbers look wrong?

Use the available Chinese preset or a font supported by the browser, then check the font size and margins. Mixed page sizes may require a page-by-page review to catch clipping or overlap.

03

TOPIC

Images to PDF

Arrange JPG, PNG and WebP images into one new PDF with page and quality controls.

Open Images to PDF

Which image formats are supported?

The tool supports JPG, JPEG, PNG and WebP images. Before adding them, check the files are complete, oriented correctly and in the order you want to read them.

Can I reorder images and change page orientation?

Yes. Arrange the image order in the organizer and choose automatic, portrait or landscape orientation when available. Review the first and last page before creating the PDF.

Should I choose A4, Letter or Fit image?

A4 suits common office printing, Letter suits North American paper workflows, and Fit image keeps the source image dimensions as the priority. Fixed paper sizes should be checked for cropping and unexpected whitespace.

How does quality affect the PDF?

Best quality is useful for archiving and printing but creates larger files. Balanced is suited to everyday sharing, while Smaller is useful for quick transfer. Very large source images can often be reduced without a visible loss for screen use.

Does Images to PDF recognise text in photos?

No. The tool places images onto PDF pages and does not provide OCR. Text inside a photo normally remains pixels rather than searchable or editable PDF text.

04

TOPIC

Watermark PDF

Add a text or image watermark with control over placement, opacity, rotation and page range.

Open Watermark PDF

Should I use a text or image watermark?

Text works well for CONFIDENTIAL, DRAFT or COPY notices. Images are better for logos, icons or prepared brand artwork. A transparent PNG usually avoids a distracting white rectangle.

What is the difference between single and tiled watermarks?

A single watermark creates one clear mark in a chosen position. A tiled watermark repeats across the page for confidentiality, copyright or branding. Lower opacity helps keep tiled watermarks readable and unobtrusive.

Can a watermark apply to only selected pages?

Yes. Choose all pages, a range, odd or even pages, or an exclusion rule. Use the preview to check covers, appendices and landscape pages before applying the watermark.

How should I set size, opacity and rotation?

Size controls the area covered, opacity controls how strongly the mark competes with the document, and rotation creates a diagonal notice. Start conservatively and adjust from the preview.

Should the watermark sit over or behind the content?

Over content is more visible for status or warning messages. Behind content behaves more like a background for branding or copyright. In both cases, verify small text, tables and signature areas remain readable.

05

TOPIC

Split PDF

Split by visual dividers, page ranges or fixed page counts, or extract selected pages.

Open Split PDF

What is the difference between splitting and extracting pages?

Splitting creates multiple consecutive PDFs. Extraction creates new files from selected pages and can export every page separately, selected pages together or selected pages separately.

When should I use visual, range or Every N?

Visual dividers are useful when you choose break points by looking at thumbnails. Ranges suit known page groups. Every N is useful for fixed-length batches. Check the output count and page order after choosing a method.

Can I extract only a few pages?

Yes. Select the pages in the preview, then choose whether they should become one PDF or separate files. Check that covers, blank pages and restricted pages were not selected by mistake.

Will splitting change the original PDF?

The workflow creates new output files and should not overwrite the original. Keep the source file and open at least one result to check its pages, filename and content.

Why can some PDFs not be split?

Password protection, damaged objects, very large scanned pages or non-standard structures can stop previewing. Confirm you have permission to modify the file and try saving a clean copy in a mainstream PDF reader.

06

TOPIC

PDF to Image

Render all, selected or ranged PDF pages as JPG or PNG images.

Open PDF to Image

Should I choose JPG or PNG?

JPG is usually smaller and works well for web previews and quick sharing. PNG is better for lossless graphics, crisp text edges or transparent artwork. Choose based on the next use of the image.

Can I convert only certain pages?

Yes. Select all pages, a page range or selected pages, then confirm the count. Check the first and last output page before downloading.

What is the difference between 96, 150 and 300 DPI?

Higher DPI usually increases image dimensions and clarity, but also increases file size and processing time. 96 DPI suits screen previews, 150 DPI suits everyday office sharing, and 300 DPI suits printing or detailed review.

Why does one PDF create multiple images?

Each PDF page normally becomes one output image. Multi-page results may be packaged for download, depending on the current browser workflow and the number of selected pages.

What can I do when high-resolution conversion is slow?

High DPI, many pages and scanned files use more memory. Test a small range or 150 DPI first, then raise the resolution for the final export if the result needs more detail.

07

TOPIC

Files, Privacy and Boundaries

Shared guidance for file handling, privacy, compatibility and responsible use across all six tools.

Are files uploaded to a server?

Supported browser workflows are designed to read, preview and create results locally in the browser, reducing the chance that a document leaves the device. The page still loads scripts and resources, so sensitive files should be evaluated against your organisation’s policy.

Will the original file be overwritten?

The tools create a new output and should not overwrite the source file. Keep the original and open the new result before sharing it.

Can password-protected PDFs be processed?

The correct password or document permission is usually required. Do not bypass protection. Even if the file opens, confirm that you are allowed to modify, convert or export it.

Are mobile phones or public computers suitable?

Mobile is suitable for low-risk, short tasks, but precise review is harder on a small screen. Public computers may retain cache, downloads or unknown extensions and should not be used for sensitive documents.

What is the difference between the web and Windows versions?

The web version is convenient for quick browser use and common local processing. The Windows desktop version is better suited to offline work, sensitive files, batch processing and fixed-computer workflows.

Can the tools guarantee legal validity?

No. Visible stamps, watermarks, page numbers and image conversion do not provide legal certification, digital signatures, notarisation or identity verification. Legal effect depends on the document, signing process, law and business context.

Why can the export look different from the preview?

Page size, orientation, scan margins, fonts, image resolution and browser memory can affect the result. Review representative pages before export and open the downloaded file in a PDF or image viewer afterwards.

What information helps when reporting a problem?

Include the tool, steps, browser or operating system, page count, visible error and whether a redacted test file reproduces it. Do not send confidential originals in the first report.

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Take the answer back to the tool.

Choose the workflow that matches your file, configure it, then review representative pages before export.

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