Large file uploads in a web browser are problematic, even in 2018. If working with a poor network connection, uploads can fail and have to be retried from the start.

At Auphonic, our users have to upload large audio and video files, or multiple media files when creating a multitrack production. To minimize any potential issues, we integrated various external services which are specialized for large file transfers, like FTP, SFTP, Dropbox, Google Drive, S3, etc.

To further minimize issues, as of today we have also released resumable and chunked direct file uploads in the web browser to

If you are not interested in the technical details, please just go to the section Resumable Uploads in Auphonic below.

The Problem with Large File Uploads in the Browser

If using either mobile networks (which remain fragile) or unstable WiFi connections, file uploads are often interrupted and will fail. There are also many areas in the world where connections are quite poor, which makes uploading big files frustrating.

After an interrupted file upload, the web browser must restart the whole upload from the start, which is a problem when it happens in the middle of a 4GB video file upload on a slow connection.
Furthermore, the longer an upload takes, the more likely it is to have a network glitch interrupting the upload, which then has to be retried from the start.

The Solution: Chunked, Resumable Uploads

To avoid user frustration, we need to be able to detect network errors and potentially resume an upload without having to restart it from the beginning.

To achieve this, we have to split a file upload in smaller chunks directly within the web browser, so that these chunks can then be sent to the server afterwards.
If an upload fails or the user wants to pause, it is possible to resume it later and only send those chunks that have not already been uploaded.
If there is a network interruption or change, the upload will be retried automatically.

Companies like Dropbox, Google, Amazon AWS etc. all have their own protocols and API's for chunked uploads, but there are also some open source implementations available, which offer resumable uploads:

resumable.js [link]:
"A JavaScript library providing multiple simultaneous, stable and resumable uploads via the HTML5 File API"
This solutions is a JavaScript library only and requires that the protocol is implemented on the server as well. [link]:
"Open Protocol for Resumable File Uploads" offers a simple, cheap and reusable stack for clients and servers (in many languages). They have a blog with further information about resumable uploads, see tus blog.
plupload [link]:
A JavaScript library, similar to resumable.js, which requires a separate server implementation.

We chose to use resumable.js and developed our own server implementation.

Resumable Uploads in Auphonic

If you upload files to a singletrack or multitrack production, you will see the upload progress bar and a pause button, which is one way to pause and resume an upload:

It is also possible to close the browser completely or shut down your computer during the upload, then edit the production and upload the file again later. This will just resume the file upload from the position where it was stopped before.
(Previously uploaded chunks are saved for 24h on our servers, after that you have to start the whole upload again.)

In case of a network problem or if you switch to a different connection, we will resume the upload automatically.
This should solve many problems which were reported by some users in the past!

You can of course also use any of our external services for stable incoming and outgoing file transfers!

Do you still have Uploading Issues?

We hope that uploads to Auphonic are much more reliable now, even on poor connections.

If you still experience any problems, please let us know.
We are very happy about any bug reports and will do our best to fix them!

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