What are some alternatives?
When comparing A1 Sitemap Generator and Ahrefs, you can also consider the following products
DYNO Mapper - Create Sitemaps with the DYNO Mapper Visual Sitemap Generator.
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.
WonderWebWare Sitemap Generator - Sitemap Generator is freeware program that will help you to automatically generate site maps for google, bing and yahoo in their respective file formats.
Moz - Backed by industry-leading data and the largest community of SEOs on the planet, Moz builds tools that make inbound marketing easy.
GlooMaps - Create your visual sitemap on the go - easy peasy
Serpstat - Search analytics, Rank tracking, Backlink analysis and Site Audit tool.