How does URL length affect email deliverability?
Summary
What email marketers say10Marketer opinions
Email marketer from Neil Patel's Blog shares that while not a direct ranking factor, very long URLs can increase the size of your email and potentially lead to clipping issues, especially on mobile devices, which can indirectly impact deliverability and user experience.
Marketer from Email Geeks explains that the biggest issue with long URLs she faced was the added weight to the code causing clipping in Gmail, potentially hiding the unsubscribe footer.
Email marketer from Reddit responds that very long URLs *used* to be a trigger for some spam filters, but it's less common now. He advises to focus on domain reputation and avoiding shady URL shorteners.
Email marketer from EmailOctopus Blog responds that while URL length isn't a primary factor, using URL shorteners excessively or linking to low-reputation domains can negatively impact your sender reputation and deliverability.
Marketer from Email Geeks shares that there's a 998 character limit for any line of text in an email message. Long URLs without CR/LF characters can cause delivery issues.
Marketer from Email Geeks explains that Outlook has issues with long URLs, with different character limits for various Outlook versions (Outlook 2007 - 975, Outlook 2010 - 1033, Outlook 2013 - 2048).
Marketer from Email Geeks explains that the length of a URL is largely a myth, but individual org-level filters can have their own rules. Problems with URLs arise from concealing the final destination, linking to low reputation websites, and serving different content to bots.
Email marketer from Litmus Blog shares that while there isn't a direct penalty for URL length, long URLs can make emails look messy and unprofessional. Using descriptive anchor text is recommended instead of displaying the full URL.
Email marketer from Stack Overflow shares that the limits for HTML links in Outlook have changed over time and very long URLs can cause issues
Email marketer from Email Marketing Forum responds that the URL length can impact the HTML file size
What the experts say4Expert opinions
Expert from Email Geeks shares that she recalls a possible negative score for very long URLs in the early 2000s but stopped flagging it in client audits over a decade ago. She mentions one email testing service flags it, but it seems more like an upsell for their link shortening service.
Expert from Email Geeks explains that SpamAssassin flags URLs with random hex letters/numbers, often associated with long URLs. Also, some sending platforms may not encode message bodies correctly, leading to issues with long lines if a long URL is present.
Expert from Spamresource responds that long URLS are one way to obfuscate destination and domain, but other URL parameters also hide the true destination URL of the link.
Expert from Word to the Wise explains that line length matters, and long URLs can contribute to lines exceeding the limit. She also adds the caution that very long URLs may be an attempt to avoid URL reputation systems.
What the documentation says3Technical articles
Documentation from Mailchimp explains that while URL length isn't explicitly mentioned, using trackable links that are too long can affect deliverability in some email clients if your code is poor. Using URL shorteners is not recommended.
Documentation from Google Postmaster Tools Help explains that while URL length itself isn't explicitly penalized, excessively long or obfuscated URLs can be a signal to spam filters. Clear and concise URLs are preferred.
Documentation from RFC 5322 specifies a line length limit of 998 characters, but recommends lines be kept to 78 characters. Long URLs, if not properly encoded, can contribute to exceeding these limits and cause delivery problems.