Multi Host - Self-Hosted Image Hosting Platform
Updated October 2025
Multi Host is a self-hosted platform designed for managing image and file uploads at scale. It provides administrators with granular control over storage allocation, thumbnail generation, user permissions, and content moderation. The system operates on standard PHP hosting environments and supports a range of storage backends for flexibility in deployment.
Platform Overview
At its core, Multi Host handles the complete lifecycle of uploaded content: receiving files from users, validating their format and size, generating thumbnails where appropriate, storing originals in configurable locations, and serving content through optimised delivery paths. The platform separates storage concerns from presentation, allowing administrators to adjust backend infrastructure without disrupting the user-facing interface.
The architecture follows a straightforward request flow. When a user uploads an image, the system first validates the file against configured rules—checking MIME type, file extension, dimensions, and file size. Valid uploads proceed to the processing pipeline, which may include thumbnail generation, metadata extraction, and storage operations. Failed validations return informative error messages without consuming server resources on invalid content.
Typical Setup Patterns
Most installations follow one of three deployment patterns, depending on scale and infrastructure requirements.
Single-Server Deployment suits smaller operations where all components—web server, PHP processor, and file storage—run on the same machine. This approach minimises complexity and works well for personal hosting or small communities. Storage typically uses the local filesystem, with uploads stored in a dedicated directory outside the web root.
Separated Storage Deployment moves file storage to dedicated infrastructure while keeping the application server lightweight. Common configurations include NFS mounts, object storage services, or dedicated file servers. This pattern improves scalability and simplifies backup procedures by isolating frequently-changing upload data from application code.
Distributed Deployment scales horizontally by running multiple application servers behind a load balancer, all connected to shared storage. This architecture handles high traffic volumes and provides redundancy, though it requires careful attention to session handling and cache invalidation across nodes.
Regardless of pattern, the application expects certain filesystem permissions and directory structures. The installation documentation covers these requirements in detail, but administrators should pay particular attention to the separation between public-facing directories (where thumbnails may be served directly) and private storage (where original uploads reside).
Key Considerations
Storage Management
Storage capacity planning depends heavily on your expected upload volume and retention policies. Multi Host tracks storage usage per user and globally, allowing administrators to set quotas at both levels. When quotas approach limits, the system can notify users, reject new uploads, or trigger cleanup procedures depending on configuration.
The platform supports multiple storage strategies for different content types. Images might route to fast local storage for thumbnail generation, while completed uploads move to cheaper long-term storage. Administrators define these routing rules in the configuration, balancing performance against cost.
Original files and generated thumbnails can use different storage locations. Many deployments keep thumbnails on fast, CDN-backed storage while storing originals on more economical backends. This separation reduces costs without affecting the user experience, since most requests fetch thumbnails rather than full-resolution images.
Thumbnail Generation
The thumbnail system processes uploaded images into standardised sizes for display throughout the interface. Configuration options control which sizes to generate, quality settings for compressed formats, and whether to preserve aspect ratios or crop to exact dimensions.
Processing happens asynchronously for large uploads, queuing thumbnail generation to avoid blocking the upload response. Users see placeholder images until processing completes, typically within seconds for standard image sizes. Administrators can monitor the processing queue and adjust worker allocation based on throughput requirements.
For high-volume installations, consider offloading thumbnail generation to dedicated workers or external services. The plugin architecture allows integration with image processing APIs, reducing load on application servers during traffic spikes.
Quota Management
User quotas prevent any single account from consuming disproportionate storage resources. The system tracks usage in real-time, updating counters as uploads complete and files are deleted. Quota enforcement happens at upload time—the system rejects files that would exceed the user's allocation before writing them to storage.
Administrators can assign quotas directly to users or through group membership. Group-based quotas simplify management for installations with defined user tiers, such as free accounts with limited storage and premium accounts with higher allocations. Individual overrides remain available for specific users who need exceptions.
The quota system accounts for both original files and generated derivatives. When calculating usage, administrators can choose whether thumbnails count against user quotas or only original uploads. Most installations exclude system-generated thumbnails from quota calculations, since users don't directly control their creation.
Abuse Prevention
Public-facing upload services attract abuse attempts ranging from spam to malware distribution. Multi Host includes several defensive layers that work together to filter problematic content before it reaches storage.
Rate limiting restricts how quickly users can upload files, preventing rapid-fire spam attempts. Limits apply per user account and per IP address, catching both authenticated abuse and anonymous attacks. The configuration allows different rate limits for different user groups, giving trusted users more flexibility while constraining new accounts.
Content validation goes beyond basic MIME type checking. The system can analyse image files for embedded scripts, unusual metadata, or characteristics common in exploit attempts. While no validation system catches everything, layered checks significantly reduce the attack surface.
Moderation queues hold uploaded content for review before public visibility. Administrators can enable moderation for all uploads, only for new users, or based on content characteristics. The moderation interface presents pending items with metadata and preview thumbnails, streamlining the review process.
Integration with Documentation
For detailed setup instructions, see the Getting Started guide. Storage configuration options are covered in Storage and Paths, while security hardening recommendations appear in the Security Checklist.
Operational procedures for ongoing maintenance—including backup strategies, log analysis, and performance monitoring—appear throughout the guides section. The Securing File Uploads guide provides essential reading for any public-facing deployment.
Frequently Asked Questions
Multi Host runs on standard PHP hosting with version 7.4 or later. It requires the GD or ImageMagick extension for thumbnail generation, adequate filesystem permissions for upload directories, and a MySQL or MariaDB database. The hosting requirements documentation covers specific version compatibility and extension dependencies.