File Format Reference Guide
A complete reference for 60+ common file formats. Find the right format for your needs, understand the differences, and convert between formats with free tools.
Audio Formats
Audio formats differ in compression method, file size, and quality. Lossy formats (MP3, AAC, OGG) are smaller but discard some audio data. Lossless formats (FLAC, WAV, ALAC) preserve full quality but produce larger files.
| Format | Description |
|---|---|
| MP3 | Most common audio format. Lossy compression, small files, universal playback support. |
| WAV | Uncompressed audio. Large files, lossless quality. Standard for audio editing and production. |
| AAC | Advanced Audio Coding. Better quality than MP3 at same bitrate. Default for Apple devices and YouTube. |
| OGG Vorbis | Open-source lossy format. Good compression, royalty-free. Used in games and web audio. |
| FLAC | Free Lossless Audio Codec. Compresses without quality loss. 50-60% of WAV size. |
| M4A | MPEG-4 audio container, typically AAC encoded. Default format for iTunes and Apple Music. |
| WMA | Windows Media Audio. Microsoft proprietary format. Declining use, mostly legacy Windows applications. |
| AIFF | Audio Interchange File Format. Apple's uncompressed audio format. Similar to WAV but Mac-native. |
| Opus | Modern open-source codec. Excellent at all bitrates. Used in VoIP, streaming, and WebRTC. |
| ALAC | Apple Lossless Audio Codec. Lossless compression for Apple ecosystem. Similar to FLAC but Apple-native. |
Need to reduce audio file size? Use our Audio Compressor to convert any format to optimized MP3. Read more: Audio Bitrate Explained
Image Formats
Image formats balance file size, quality, and feature support (transparency, animation). JPEG is best for photos, PNG for graphics with transparency, and WebP for modern web images that need both small size and quality.
| Format | Description |
|---|---|
| JPEG | Most common image format. Lossy compression ideal for photos. Adjustable quality from 1-100%. |
| PNG | Lossless format with transparency support. Best for screenshots, graphics, and text-heavy images. |
| WebP | Google's modern format. 25-35% smaller than JPEG at same quality. Supports transparency and animation. |
| GIF | Supports animation and transparency. Limited to 256 colors. Best for simple animations and icons. |
| HEIC | Apple's default photo format since iOS 11. 50% smaller than JPEG. Limited browser/app support. |
| SVG | Vector format using XML. Scales to any size without quality loss. Best for logos, icons, and illustrations. |
| BMP | Bitmap format. Uncompressed, very large files. Legacy Windows format, rarely used today. |
| TIFF | Tagged Image File Format. Supports lossless compression and multiple layers. Standard in publishing and photography. |
| AVIF | AV1-based image format. Better compression than WebP. Growing browser support, excellent for web images. |
| ICO | Icon format for Windows and web favicons. Contains multiple sizes in one file. |
| RAW | Unprocessed sensor data from digital cameras. Maximum editing flexibility. Very large files. |
| PSD | Adobe Photoshop native format. Preserves layers, masks, and editing history. |
Convert between image formats with our free tools: PNG to JPG, Image to WebP, or Resize Image. Read more: Best Image Format for Web
Video Formats
Video formats are containers that hold video and audio streams encoded with codecs. MP4 with H.264 is the universal choice. WebM offers better compression for web. MKV is popular for high-quality archival.
| Format | Description |
|---|---|
| MP4 | Most widely supported video format. Uses H.264/H.265 codecs. Plays on virtually every device. |
| WebM | Google's open web video format. Uses VP8/VP9 codecs. Smaller than MP4 at similar quality. |
| MKV | Matroska container. Supports unlimited tracks, chapters, and metadata. Popular for high-quality video. |
| MOV | Apple QuickTime format. High quality, large files. Default for iPhone video recording. |
| AVI | Audio Video Interleave. Microsoft legacy format. Large files, limited codec support. |
| WMV | Windows Media Video. Microsoft proprietary. Declining use outside Windows ecosystem. |
| FLV | Flash Video. Formerly dominant for web video. Obsolete since Flash end-of-life in 2020. |
| GIF (animated) | Short animations without sound. Very large file sizes compared to video. Max 256 colors per frame. |
Convert videos with our free tools: Video to MP4, Compress Video, or Video to GIF. Read more: H.264 vs H.265
Document Formats
Document formats handle text, formatting, and layout differently. PDF preserves exact appearance across devices. DOCX is editable in Word. HTML is for web content. Choose based on whether you need editability or consistent display.
| Format | Description |
|---|---|
| Portable Document Format. Preserves layout across all devices. Standard for sharing documents. | |
| DOCX | Microsoft Word format since 2007. XML-based, editable. Standard for business documents. |
| DOC | Legacy Microsoft Word format (pre-2007). Binary format, less interoperable than DOCX. |
| XLSX | Microsoft Excel format. XML-based spreadsheets with formulas, charts, and pivot tables. |
| PPTX | Microsoft PowerPoint format. Presentations with slides, animations, and embedded media. |
| Plain Text | Unformatted text. Universal compatibility, smallest file size. No styling or images. |
| HTML | HyperText Markup Language. Web page format with structure, styling, and interactivity. |
| RTF | Rich Text Format. Basic formatting with broad compatibility. Good for simple cross-platform documents. |
| ODT | OpenDocument Text. Open standard used by LibreOffice and Google Docs export. |
| CSV | Comma-Separated Values. Plain text data format. Universal for data exchange between applications. |
Work with documents: Word to PDF, Merge PDF, or Sign PDF. Read more: PDF vs DOCX
Archive Formats
Archive formats bundle multiple files into one and optionally compress them. ZIP has universal support. 7Z offers the best compression ratios. TAR is the standard on Linux, usually paired with GZIP.
| Format | Description |
|---|---|
| ZIP | Most common archive format. Built-in support on Windows, macOS, and Linux. Good compression. |
| RAR | Roshal Archive. Better compression than ZIP. Requires WinRAR or compatible software. |
| 7Z | 7-Zip format. Best compression ratios. Open source. Supports AES-256 encryption. |
| TAR | Tape Archive. Bundles files without compression. Often combined with gzip (.tar.gz) or bzip2 (.tar.bz2). |
| GZIP | GNU Zip compression. Single-file compression. Standard for web content compression and Linux. |
Create or extract archives: ZIP Files or Unzip Files. Read more: ZIP vs RAR
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Open Format Finder →Quick Format Recommendations
Best for web images
WebP for modern browsers, JPEG as fallback. Convert to WebP
Best for sharing documents
PDF for consistent layout. Convert Word to PDF
Best for audio quality
FLAC for lossless, 320kbps MP3 for portable. Compress Audio
Best for video sharing
MP4 with H.264 for universal playback. Convert to MP4
Best for logos and icons
SVG for scalability, PNG for compatibility. Convert to PNG
Best for email attachments
ZIP for multiple files, compressed JPEG for photos. Create ZIP