What is the appropriate address field setting?

The default address – s3.amazonaws.com – is probably what you’re looking for. You only need to change this if you’re using a custom S3-like server.

Although S3 requires you to connect to the region associated with your buckets, we handle this for you behind the scenes after listing your buckets.

Can I set custom S3 upload headers?

In Transmit 5, yes! These custom headers can be specified in the Cloud section of Transmit’s Preferences. Click Default under Extension (setting the rule for all file extensions), then add a new rule.

Is there a file size limit when uploading files to S3?

S3 requires any file over 5 GB to be uploaded using multi-part uploading. Currently, this is supported in Transmit 5, Transmit for iOS, Coda 2, and Code Editor.

Is Amazon Glacier supported?

Not currently. Glacier storage is organized in a very different way from S3. This is something we are considering for a future update.

As a workaround you can create an S3 bucket with a Glacier lifecycle policy which will archive your uploads automatically. Amazon has written more information about this on their website. Note that this workaround is only for getting files into Glacier— there’s no way to retrieve files from Glacier with Transmit at this time.