Filestack is a file handling platform made by Filestack, a company headquartered in San Antonio, Texas. It gives a web or mobile app three layers through one integration: upload, transform and deliver.
The upload layer is a drop-in file picker, added with a few lines of JavaScript, that accepts files from the local disk and more than 20 sources such as Google Drive, Dropbox and Instagram, with resumable uploads. Its Content Ingestion Network accepts each upload at the nearest edge node, returns a file handle at once and copies the file in the background to S3, Google Cloud Storage or Azure. The transform layer changes images, documents, audio and video on Filestack's servers, controlled by URL parameters, for example cropping or format conversion. The delivery layer serves files through a global CDN (content delivery network, a set of servers spread around the world) with signed URLs. Virus detection and content moderation can run on every file.
It is a hosted service with a free plan and monthly plans sized by bandwidth, uploads, transformations and storage.