SonoFiles Help Center

Uploading and opening files

The tool says the file type is unsupported

Check the actual format, not only the filename. Renaming .docx to .pdf does not convert the file. Some formats also have several generations or variants, such as legacy .doc versus modern .docx. Use a tool that explicitly accepts the format you have.

The file is valid but still will not load

The file may be damaged, unusually large, encrypted, or use a feature the browser library cannot parse. Try opening it in its normal desktop or mobile application first. If that application reports a repair, corruption or password warning, resolve that issue before using a browser tool.

A very large file freezes or closes the tab

Browser tools work within the memory available to the current device. High-resolution scans, large slide decks and image-heavy PDFs can require much more memory than their file size suggests because pages and images are decompressed while processing. Close unnecessary tabs, try a desktop browser with more memory, reduce the source file where practical, or process it in smaller parts.

Downloads and finished files

Nothing happens when I click Download

Check the browser's download permission and download history. Some browsers block repeated automatic downloads or route files to a default Downloads folder without showing a large confirmation. If the tool has a Generate, Convert or Apply button, make sure you created the latest result after changing settings.

The downloaded file has an unfamiliar name

SonoFiles may add a short operation label so the result does not overwrite the original. You can rename the finished file after download, but keep the correct extension. Avoid removing .pdf, .docx, .xlsx or another required suffix unless your operating system hides extensions automatically.

Can I safely delete the original?

Wait until the new file has been opened and accepted by its destination. For destructive operations such as redaction or page deletion, keeping the source is especially important because the output is intentionally different.

When a converted document does not look identical

Document formats use different layout models. Word text can reflow, Excel sheets can be wider than printable pages, PowerPoint objects can depend on slide masters, and PDFs can position each visible item at fixed coordinates. Converting between these models may require approximation.

• Fonts: unavailable fonts can change character widths and line breaks.
• Tables: complex merged cells and nested tables can be difficult to reproduce.
• Spreadsheets: print areas, formulas, hidden cells and very wide columns can change pagination.
• Presentations: animations, video, SmartArt, grouped shapes and master-layout features may not translate fully to a static PDF.
• PDF extraction: a PDF stores what a page looks like, not necessarily the original paragraph, table or spreadsheet structure.

For a document that must preserve exact design, inspect the converted result page by page. If you still have the source application, exporting directly from that application can be more faithful for highly complex files.

PDF help: scans, rotation, page size and protection

The PDF looks like text but text extraction returns nothing

It is probably an image-only scan. Use OCR rather than ordinary text extraction. If you can drag over words and copy them in a PDF viewer, the file already contains a text layer and direct extraction is usually preferable.

Some pages are sideways

PDFs can store a page rotation flag separately from the page's raw dimensions. A well-behaved tool should respect the displayed orientation, but unusual or damaged files can still behave unexpectedly. Verify any output that depends on exact visual coordinates, such as signatures, crops or redactions.

Pages have different sizes

Mixed-size PDFs are valid. A single file may combine A4, US Letter, Legal, receipts or scanned pages. If your destination requires one paper size, use a page-size conversion workflow rather than assuming all pages already match.

The PDF asks for a password

A PDF can require a password to open, or it can contain owner permissions that restrict editing, copying or printing. SonoFiles should not be used to bypass access you are not authorized to remove. If you know the required password and have permission, use an appropriate unlock workflow and verify the resulting file.

Privacy and browser-local processing

Many SonoFiles operations are designed to process selected files in the browser when technically practical. In that model, the primary transformation happens on your device instead of uploading the source file to a SonoFiles conversion server. The relevant tool page should describe the processing model for that specific feature.

Browser-local processing reduces one category of exposure, but it does not make every environment automatically safe. A web page may still request ordinary site assets or libraries, and your device can have extensions, synced browser features or other software. For confidential corporate, medical, legal, financial or identity documents, follow the security requirements that apply to the document owner.

See the Privacy Policy for broader information about site data and the Cookie Policy for browser storage and cookies.

Using SonoFiles on phones and tablets

Most browser file tasks can work on modern mobile devices, but phones typically have less available memory and different file-picker behavior than desktop computers. If a large PDF or presentation fails on mobile, trying the same file on a desktop browser can distinguish a device-resource limit from a damaged source file.

For drag-and-position tools, use deliberate taps and short drags. Zooming the browser page can sometimes compete with a tool's touch interaction. If the control feels difficult, return the browser zoom to its normal level and retry. Mobile downloads may appear in the browser's download manager, the Files app, or a device-specific Downloads folder.

Signing and redacting PDFs

Does placing a signature image create a certificate-backed digital signature?

No. A visible signature placed on a page is an electronic visual mark. It does not automatically provide certificate-based cryptographic identity verification, a trusted timestamp or a formal validation chain. If a recipient requires a qualified, advanced or certificate-backed digital signature, use a service or application that explicitly supports that requirement.

Is drawing a black box over text enough to redact it?

Not necessarily. Safe redaction requires the underlying sensitive content to be removed from the saved output, not merely hidden visually. After redaction, reopen the output and test whether the information can still be searched, selected, copied or extracted.

OCR and extracted text

OCR is probabilistic. Accuracy can decrease with handwriting, low contrast, skew, blur, unusual fonts, complex columns and mixed languages. Review names, numbers, dates and punctuation before using OCR output as authoritative data. If the document already has a clean text layer, direct PDF-to-text extraction is usually more accurate than running OCR again.

Still need help?

If the issue is specific to a SonoFiles tool, contact us with the tool name, browser and device, source file type, and a description of what happened versus what you expected. Do not send confidential source documents unless a support process specifically requests them.

Use support@sonofiles.com for product help, or visit the Contact page for privacy, legal and general contact channels.