Frequently Asked Questions
Answers to the most common questions about using Free Document Viewer, handling your files, and optimizing your preview experience.
What document formats can I preview?
Free Document Viewer supports DOCX, PPTX, XLSX, TXT, and many source-code formats. Office files are rendered with dedicated viewers, while all other plain-text based formats are displayed in the code-style viewer.
Do my documents ever leave my device?
No. All file processing happens locally in your browser. We do not upload, store, or transmit your documents to any server, and files are cleared from memory when you close the viewer.
How large can my files be?
TXT and other plain-text files without a MIME type are limited to 3 MB. Files with a recognized MIME type can be up to 5 MB. These limits keep rendering fast and reliable in the browser.
Why do heavy libraries load only when needed?
To keep initial load times quick, we lazy-load third-party preview libraries (for DOCX, PPTX, and XLSX) only when you open a file that requires them. This dynamic import strategy improves performance for users who only need lightweight previews.
Can I use the viewer on mobile devices?
Yes. The uploader detects touch devices and adapts the call-to-action text for mobile users. You can tap to pick a file or rely on the drag-and-drop experience on desktop.
What should I do if a preview fails?
First, confirm the file size is under the supported limit and the format is one of the supported types. If the file is password-protected or uses uncommon fonts, the preview may fail. Try exporting the document to a standard format and re-uploading.
Does the viewer support multiple languages?
Yes. The landing experience is localized for English, Simplified Chinese, Japanese, Korean, Traditional Chinese, German, French, Spanish, Portuguese, Arabic, Russian, Vietnamese, and Thai. You can switch languages from the top navigation.
How do I contact support?
Send an email to loveleuvi@gmail.com. We aim to respond within 48 hours with guidance or fixes.