Most applications need file uploads - profile pictures, documents, images, videos. Knowing how to handle files properly is a must-have skill for web developers.
This project teaches you about binary data, multipart forms, and image processing. You'll learn how to resize images, generate thumbnails, and store files efficiently without slowing down your server.
File validation is crucial for security. Users might try to upload malicious files or files that are too large. You'll learn how to validate on both frontend and backend to keep your application safe.
File handling is a common requirement. Users need to upload profile pictures, documents, videos, and other files. Learning how to handle uploads safely and efficiently is important.
This project teaches you about binary data, image processing, and storage options. You'll learn how to resize images, which saves bandwidth and improves performance.
You'll also learn about progress tracking, which gives users feedback during long uploads. The patterns you learn here apply to any kind of file processing - videos, audio, PDFs, or images.
Build a comprehensive file handling system that accepts uploads, processes images, generates thumbnails, and stores files efficiently. This project teaches you how to work with binary data, handle large file uploads, implement background processing, and manage cloud storage.
You'll learn essential skills for building applications that need to handle user-generated content like profile pictures, documents, or media files.
Handle multipart form data and file uploads
Process and manipulate images programmatically
Implement upload progress tracking
Work with file storage (local or cloud)
Validate file types and sizes
Generate and serve multiple image sizes
Accept file uploads via drag-and-drop or file picker
Support multiple file types (images, PDFs, documents)
Validate file size (max 10MB) and type before upload
Show upload progress bar with percentage
Process uploaded images (resize, compress, generate thumbnails)
Store files locally or in cloud storage (AWS S3 or similar)
Generate unique filenames to prevent collisions
Create three image sizes: thumbnail (150px), medium (500px), large (1200px)
Store file metadata in database (filename, size, type, URL, uploadedBy)
Display uploaded files in gallery with preview
id, originalName, filename (unique), fileType, fileSize
uploadedBy (userId), uploadDate
urls: { original, thumbnail, medium, large }
dimensions: { width, height }
isPublic (boolean), downloadCount
POST /api/files/upload - Upload single or multiple files
GET /api/files - Get user's uploaded files
GET /api/files/:id - Get file metadata
GET /api/files/:id/download - Download original file
DELETE /api/files/:id - Delete file and all variants
GET /api/files/:id/thumbnail - Serve thumbnail
GET /api/files/:id/medium - Serve medium size
GET /api/files/:id/large - Serve large size
Accept upload and validate file type and size
Generate unique filename using UUID or timestamp
Read image dimensions from original file
Create thumbnail (150x150, cropped to square)
Create medium version (500px max width/height, maintain aspect ratio)
Create large version (1200px max width/height, maintain aspect ratio)
Compress all versions to reduce file size (85% quality)
Save all versions to storage
Save metadata to database
Return URLs for all versions to client
Drag-and-drop upload zone with visual feedback
File picker button for traditional upload
Multiple file selection support
Preview images before upload
Upload progress bars for each file
Cancel upload button while uploading
Gallery view showing all uploaded files
File cards with preview, name, size, and actions
Modal for full-size image viewing
Download and delete buttons for each file
Use multer middleware for handling multipart uploads
Implement image processing with Sharp library
Handle large file uploads without blocking server
Track upload progress using XMLHttpRequest or axios progress events
Implement chunked uploads for files larger than 5MB
Generate secure URLs for file access
Clean up temporary files after processing
Implement proper error handling (network failures, processing errors)
Validate file type on both client and server
Check file size before uploading (client) and after receiving (server)
Verify image files are actually images (check magic bytes)
Sanitize filenames to prevent path traversal attacks
Limit number of simultaneous uploads per user
Check available storage quota before accepting upload
Add image rotation and cropping tools
Implement automatic image orientation correction
Add watermark to uploaded images
Support video thumbnail generation
Implement file sharing with expiring links
Add bulk download as ZIP file
Create image gallery with categories/albums
Implement lazy loading for gallery images
Multer: Multer docs show how to handle file uploads in Express. Start with basic examples.
Sharp: Sharp docs for image processing. It's fast and easy to use for resizing and compressing.
FormData: MDN docs on FormData API. This is how browsers send files to servers.
Progress Events: Look up "XMLHttpRequest progress" or "axios upload progress".
Cloud Storage: AWS S3 docs or Cloudinary docs for cloud storage options.
File Validation: Search for "file type validation Node.js" and "magic bytes file verification".
Multer: Multer documentation on npm. It handles multipart/form-data for file uploads.
Sharp: Sharp image processing library docs. It's fast and has simple API for resizing images.
File Upload Tutorial: Search for "Node.js file upload tutorial" or "Express file upload".
FormData: MDN docs on FormData API. Learn how to send files from frontend.
Progress Events: Search for "upload progress bar JavaScript" or "XMLHttpRequest progress".
Cloud Storage: Look up AWS S3 or Cloudinary tutorials if you want to use cloud storage.
Files upload successfully with progress tracking
All image sizes are generated correctly
Upload fails gracefully with clear error messages
Gallery loads quickly even with many files
Deleted files are removed from storage and database
File URLs work correctly and serve images
System handles multiple simultaneous uploads
Images maintain quality after processing
Study Multer documentation for file uploads
Learn Sharp library for image processing
Research AWS S3 or Cloudinary for cloud storage
Explore FormData API for file uploads
Look into progress events for XMLHttpRequest
Hint: Start with local file storage to keep things simple, then migrate to cloud storage once everything works. This makes debugging easier since you can see the files directly.
Always validate files on the server even if you validate on the client. Users can bypass client-side validation by manipulating requests directly.
Submit Your Project
Once you've completed this project, submit your GitHub repository link below: