Vercel Blob is an object storage service made by Vercel. Object storage keeps whole files (called objects, or here blobs) under a name in a flat store, as Amazon S3 does, instead of in a file system on one server. It holds images, videos, documents and other files that a web app uploads or serves, up to 5 TB per file.
A program uploads a file with the Vercel Blob SDK for JavaScript or Python, at build time or when a user submits it, and receives a URL. Each store lives in one of 19 regions, and Vercel's CDN (content delivery network, servers that keep copies of files close to users) caches the files. A store is either public, where anyone with the URL can read a file, or private, where reads need a token and pass through the app's own functions. Stores are created in the Vercel dashboard or the command-line tool and can be connected to many projects.
It is a hosted service on all Vercel plans, billed by usage: stored gigabytes per month, upload and read operations, and data transfer, with a small included amount.