Methods and systems are disclosed that facilitate client-side encoding of content. Certain embodiments involve sending a user's client device items for encoding content that will be uploaded to an upload recipient. In some cases, a client-device may receive an encoding application or application component for performing the encoding. In some cases, a client device may receive upload parameter information for the upload. The embedded content may include an identifier that allows confirmation that it was encoded according to the parameters. Embodiments provide various mechanisms for an upload recipient to guarantee or otherwise trust that uploaded content has been appropriately encoded and/or encrypted by a user. Items and instructions for uploading can be provided from the upload recipient or from a provider who is trusted by the client and the recipient with respect to encoding the content.