filelook

Generate thumbnails for any file type. Zero external dependencies - every format is decoded in pure TypeScript or bundled WASM.

Supported formats

| Format | Notes | |--------|-------| | JPEG | Baseline + progressive | | PNG | All bit depths and color types | | BMP | 24/32-bit | | GIF | First frame, with transparency | | WebP | Lossy (VP8), lossless (VP8L), animated (first frame) | | TIFF | Uncompressed | | ICO / CUR | Includes embedded PNG and BMP | | ANI | Animated cursors (first frame) | | PSD | Photoshop (composite image) | | DDS | DirectDraw Surface | | TGA | Targa | | PCX | ZSoft Paintbrush | | PBM / PGM / PPM | Netpbm formats | | QOI | Quite OK Image | | PDF | Vector graphics, embedded images, text (fallback font) | | DOCX | Word documents (text, images, layout) | | DOC | Word 97-2003 (text, images, layout) | | ODT | OpenDocument Text | | PPTX | PowerPoint slides (first slide, text, images) | | PPT | PowerPoint 97-2003 (first slide, text, images) | | XLSX | Excel spreadsheets (grid, charts, images) | | XLS | Excel 97-2003 (grid layout) | | SVG | Scalable Vector Graphics (shapes, paths, text, images) | | CSV | Auto-delimiter detection, styled table layout | | MP4 | H.264 video (first frame) — work in progress |

Install

npm install filelook

Usage

import { thumbnail, thumbnailAsBase64, thumbnailToFile } from 'filelook';

// File path or Buffer → PNG Buffer
const buf = thumbnail('./photo.webp');
const buf2 = thumbnail(fileBuffer, { width: 128, height: 128 });

// → base64 string
const b64 = thumbnailAsBase64('./photo.jpg');

// → write to disk
thumbnailToFile('./photo.jpg', './thumb.png');

Options

| Option | Type | Default | Description | |--------|------|---------|-------------| | width | number | 256 | Thumbnail width in pixels | | height | number | 256 | Thumbnail height in pixels | | type | FileType | auto-detect | Override file type detection | | fit | FitMode | 'cover' | 'cover', 'contain', or 'fill' |

Contributing

File type contributions are welcome! See CONTRIBUTING.md for a step-by-step guide on adding a new thumbnail generator.

License

Beerware