How to Convert Any File Format for Free

Someone sends you a .heic photo your PC cannot open, or a .pages document you need in .docx. File conversion does not require paid software. Here is the right free tool for every common conversion.

Documents (.docx, .pdf, .odt, .rtf)

LibreOffice (free, offline): Opens .docx, .odt, .pdf, .rtf, .txt, .html, and .epub. Open the file, then File > Save As or Export as PDF. It handles complex formatting better than online converters because it processes everything locally.

Google Docs (free, online): Upload any document to Google Drive. Right-click > Open with Google Docs. Then File > Download as .docx, .pdf, .odt, .rtf, .txt, .epub, or .html. Simple formatting converts well; complex layouts may shift.

Images (.heic, .webp, .png, .jpg)

Windows: Right-click the image, Open With > Paint. Then File > Save As and choose your format (PNG, JPG, BMP, GIF). Paint converts .heic and .webp if you have the HEIF Image Extensions installed from the Microsoft Store (free).

Mac: Open the image in Preview. File > Export. Choose format from the dropdown: JPEG, PNG, TIFF, PDF. Adjust quality slider for JPEGs.

Bulk conversion: Download XnConvert (free). Drag hundreds of images in, pick the output format, and convert them all in seconds with optional resizing.

Audio (.mp3, .wav, .flac, .m4a)

Audacity (free, offline): Open any audio file. File > Export As and choose MP3, WAV, FLAC, or OGG. For MP3 export, Audacity includes the LAME encoder built in.

VLC (free): Media > Convert/Save. Add your file, choose a profile (MP3, FLAC, WAV), and convert.

Video (.mp4, .mkv, .avi, .mov)

HandBrake (free, offline): The gold standard for video conversion. Open your file, select a preset (Fast 1080p30 works for most cases), and click Start Encode. Converts virtually any video format to MP4 or MKV. Excellent for shrinking large video files without visible quality loss.

VLC: Media > Convert/Save works for video too. Choose H.264 + MP3 (MP4) as the profile for maximum compatibility.

Ebooks (.epub, .mobi, .pdf)

Calibre (free): The universal ebook converter. Import any ebook format and convert to EPUB, MOBI, PDF, or AZW3 (Kindle). It also transfers books directly to your Kindle or e-reader via USB.

Spreadsheets and Presentations

LibreOffice Calc: Opens .xlsx, .csv, .ods. Save As any of those formats.

LibreOffice Impress: Opens .pptx, .odp. Export to PDF or save in either format.

Google Sheets/Slides: Upload to Drive, open, download in your target format.

Browser-Based Converters (When You Need Speed)

CloudConvert.com handles 200+ formats. Zamzar.com is another reliable option. Upload, choose output format, download. Both have free tiers with daily limits. Use these for quick one-off conversions of non-sensitive files. For anything containing personal data, use offline tools.

Batch Conversion for Multiple Files

Converting files one at a time is manageable, but converting 50 images or 20 documents individually is tedious. For batch image conversion, IrfanView (free for Windows) and Preview on Mac both handle bulk format changes. Select all files, choose the output format, and convert in one operation. For batch document conversion, LibreOffice includes a command-line tool that converts entire folders of documents between formats. CloudConvert allows batch uploads on its free tier. Automating batch conversion saves hours when you need to convert an entire folder of legacy files to a modern format.

Bottom Line

LibreOffice handles documents. Paint or XnConvert handles images. HandBrake handles video. Audacity handles audio. Calibre handles ebooks. All free, all offline, no file size limits.