After decades of large-scale digitization, many historical newspaper collections are just one click away via online portals developed and supported by various public or private stakeholders. Initially offering access to full text search and facsimiles visualization only, historic newspaper user interfaces are increasingly integrating advanced exploration features based on the application of text mining tools to digitized sources. As gateways to enriched material, such interfaces are however not neutral and play a fundamental role in how users perceive historical sources, understand potential biases of upstream processes and benefit from the opportunities of datafication. What features can be found in current interfaces, and to what degree do interfaces adopt novel technologies? This paper presents a survey of interfaces for digitized historical newspapers with the aim of mapping the current state of the art and identifying recent trends with regard to content presentation, enrichment and user interaction. We devised 6 interface assessment criteria and reviewed twenty-four interfaces based on ca. 140 predefined features.