Any file up to 500 MB. Drop several files and they come back as one ZIP. Many image, audio and video conversions run in your browser; anything else is uploaded and removed within the hour.
Convert your Word documents into the MOBI format to ensure perfect compatibility with your Kindle e-reader. This tool is essential for authors and readers who want to transform drafts into portable e-books.
DOCX is a feature-rich word processing format designed for editing and layout within Microsoft Word, while MOBI is a specialized e-book format optimized for reflowable text on Kindle devices. During conversion, our engine reorganizes the document structure to fit the specific constraints of the MOBI specification, ensuring that your text, headings, and lists remain intact for comfortable reading on small screens.
The conversion from DOCX to MOBI is lossless; all text content, paragraph styles, and document structure are preserved exactly as they are in the original file.
We built this project so anyone can convert files without paywalls, accounts, or hidden limits. Here is what that promise means in practice.
Every converter on ConvertX is free to use: no trials, no premium tiers, and no credit packs. We will never put core conversion features behind a subscription. Whether you convert one photo or a hundred files a week, the price stays zero.
Many image, audio, and video conversions run entirely in your browser. Your files never leave your device for those jobs. When server processing is required for documents or specialized formats, uploads are handled securely and removed automatically — typically within one hour.
A quick guide to strengths and trade-offs of popular formats — so you pick the right one before converting.
Office files, PDFs, ebooks, and plain text.
Common extensions: PDF, DOCX, XLSX, PPTX, ODT, EPUB, TXT
Raster and vector graphics for web, print, and photography.
Common extensions: PNG, JPG, WebP, AVIF, GIF, SVG, HEIC, TIFF
Clips, streams, screen recordings, and movies.
Common extensions: MP4, WebM, MOV, MKV, AVI, MPEG
Music, podcasts, voice recordings, and sound effects.
Common extensions: MP3, WAV, FLAC, OGG, AAC, M4A, OPUS
