Technical requirements for using Clowdr

Updated April 26, 2021

Getting Ready to Use Clowdr?

We want to make sure that all users have a great experience on Clowdr!

Here is the brief list of minimum technical requirements for using our platform:

  • Highly recommended to have a stable connection of at least 5Mbps (the same as YouTube recommends for 1080p)
  • Newest version of Google Chrome, Firefox, Edge or Safari
  • Windows 10 or latest macOS

Requirements for Uploads


Clowdr supports a wide range of video upload formats. However, for the best results, we recommend that you upload videos in the following format:

  • Codec: H.264 (AVC)
  • Container: MP4
  • Resolution: 1920x1080 (1080p)

Note: Clowdr does not support the following H.264 profiles: High 4:2:2, High 10-bit, High 4:4:4. Files produced in a ‘lossless’ mode are unlikely to work.

Tip: you can use the following ffmpeg command to convert many input videos to a format Clowdr accepts.

ffmpeg -i <input file> -vcodec h264 -s hd1080 -crf 23 output.mp4

Other Content Formats

Clowdr supports PDFs, and the following image formats: PNG, JPG/JPEG, GIF and WebP.

We also support uploads for text/abstracts; links; youtube and other sites video embeddings (by url to the video); and zoom links!

Tip: We also highly recommend attendees use headphones and an external camera, when available. This ensures a more comfortable experience during those long networking hours!


© Clowdr CIC 2021

Clowdr is a social enterprise dedicated to creating sustainable, inclusive and engaging conferences.

Clowdr is a UK Community Interest Company, number 12984216.

Clowdr was initially made possible thanks to support by the US National Science Foundation under awards CCF-2035003, CCF-2035101 and CCF-203500 and support from