What you'll find here
The File API and Blob objects, multipart/form-data on the wire, the Fetch and Streams APIs, base64 vs binary trade-offs, magic-byte type detection, timeout and retry logic, and the size ceilings between the browser and your handler.
Explore section →S3 presigned URL workflows, server-side validation with libmagic, ClamAV and quarantine buckets, direct-to-cloud patterns across S3, GCS and Azure Blob, post-upload transcoding, metadata indexing, lifecycle rules, and abuse protection.
Explore section →Resumable upload state machines, real-time progress over WebSockets and SSE, error-recovery patterns with exponential backoff, and client-side media preprocessing that shrinks a 12 MB photo before it ever leaves the device.
Explore section →Everything after the upload lands: HLS and DASH encoding ladders, AVIF and WebP image variants, loudness-normalised audio and captions, idempotent job orchestration, and signed, cached delivery from the edge.
Explore section →Start here
The four pages most people need first, whichever end of the pipeline they are working on.
IAM scoping, TypeScript implementation, CORS configuration, and ETag verification for direct S3 uploads.
Read article →What a multipart body actually looks like on the wire — boundaries, part headers, and the bytes in between.
Read topic →When one request beats chunking on latency and complexity — and when finer retry granularity wins.
Read article →The states a real upload moves through, and how to persist them so a dropped connection costs seconds, not megabytes.
Read topic →Newest in the library
The latest additions follow files after they land — streaming, processing and delivery — and make the uploader itself faster, more resilient and usable by everyone.
Encoding ladders for user video, HLS and DASH packaging, and playback with hls.js.
Read topic →Let S3, Cloud Storage and Azure announce finished uploads — and consume them exactly once.
Read topic →Part sizing, lazy signing, resume with ListParts, and cleaning up what users abandon.
Read topic →Bounded queues with priorities, pause and cancel, and chunk sizes tuned to the connection.
Read topic →Dropzones that work without a mouse, calm progress announcements and errors people can act on.
Read topic →Service worker loops, Background Sync outboxes and uploads that survive a closed tab.
Read topic →