Thank you for reaching out to the Constant Contact Community. It's my pleasure to assist you today. The recommended size for logos within the Sign-up Forms is 300 x 100 pixels. Additionally, this guide will provide more information on how to best prepare your images before uploading them into Constant Contact!
I hope this helps! Please let us know if there is anything else we can do for you. Thank you for choosing Constant Contact.
Amber_L Community & Social Media Support
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