The File Format Cheat Sheet: Which Format to Use and When

How to use this cheat sheet

There is rarely a single 'best' format - only the best format for a specific job. The lists below group the formats FileConverter supports by category, with a one-line note on when each is the right choice. Find your category, match your goal, and convert.

Image formats

For photos and graphics on screen, in print, or on the web:

• JPG - photos you need to open anywhere; small files, no transparency.
• PNG - logos, icons, screenshots, and anything needing transparency; lossless.
• WebP - modern web images; smaller than JPG/PNG with transparency support.
• AVIF - maximum web compression; best size at the same quality on modern browsers.
• SVG - vector logos and icons; infinitely scalable, editable as code.
• TIFF - scanning, print masters, and archival; lossless but very large.
• GIF - short simple animations; inefficient for photos or long clips.
• HEIC - iPhone photo storage; convert to JPG for wide compatibility.

Document formats

For text, spreadsheets, presentations, and books:

• PDF - final, fixed-layout sharing and printing; looks identical everywhere.
• DOCX - editable word-processing documents; the modern Word standard.
• DOC - legacy Word files; upgrade to DOCX or PDF where possible.
• TXT - raw text with no formatting; universal and tiny.
• RTF - lightly formatted text that opens in almost any word processor.
• XLSX - spreadsheets with formulas, charts, and multiple sheets.
• CSV - plain data tables for importing and exporting between systems.
• PPTX - editable slide decks; export to PDF or images to share.
• ODT / ODS - OpenDocument text and spreadsheets from LibreOffice.
• EPUB - reflowable ebooks for e-readers; convert to PDF for fixed layout.

Video formats

For clips, films, and web video:

• MP4 - the universal choice for uploading and sharing anywhere.
• MOV - Apple/QuickTime recording and editing; convert to MP4 to share.
• MKV - flexible container for multi-track archives; convert to MP4 for phones.
• WebM - efficient, royalty-free format for embedded web video.
• AVI / WMV / FLV / 3GP - legacy formats; convert to MP4 for modern playback.

Audio formats

For music, voice, and production:

• MP3 - universal lossy audio; plays on everything, small files.
• AAC - slightly better than MP3 at the same size; Apple and streaming default.
• WAV - uncompressed, lossless; the recording and editing standard.
• FLAC - lossless at half the size of WAV; ideal for archives.
• OGG - open, royalty-free lossy audio; common in games and open-source apps.

Archive formats

For bundling and compressing files:

• ZIP - the universal archive; opens natively on every major system.
• RAR - slightly better compression but needs extra software; convert to ZIP for compatibility.