Substack campaign tracking with UTM
Substack drives traffic from emailed newsletters, the web reader, and Notes. Email clicks pass through tracking and the reader app, so referrers are unreliable. UTM parameters on the destination link are the dependable way to attribute Substack traffic across email and web.
Email and web paths
Substack sends posts as email and hosts them in a web reader, with Notes as an additional surface. Email clicks frequently arrive with no referrer (mail clients vary), and clicks inside the reader app may show a Substack host rather than the originating post.
Tag your destination links with a consistent scheme — utm_source=substack, utm_medium=email for the newsletter and referral for web posts, and a utm_campaign per issue — so all of these paths roll up to one channel.
- Email opens often carry no referrer
- Reader clicks may show a Substack host
- UTM on the destination unifies email and web
Separate email from web posts
Distinguish the emailed newsletter from web reads with utm_medium so you can compare them. This mirrors the email-vs-web distinction that matters for any publication that ships both.
Click-path and referrer behaviour vary by mail client and Substack surface, so the pattern is described rather than fixed, which is why this entry is partially verified. Validate that tagged links land with their UTM intact from both email and the reader.
How it appears in analytics and logs
A tagged link arriving with utm_source set to substack identifies newsletter-driven traffic even when an email click provides no referrer or the reader app obscures it. Empty referrers are expected for email opens.
Diagnostic use case
Attribute clicks from a Substack email or post to a campaign by tagging the destination URL, instead of relying on referrers that email clients and the reader often hide.
What WebmasterID can help detect
WebmasterID records tagged Substack arrivals server-side, so you can attribute newsletter and post clicks by UTM even when email or the reader app strips the referrer.
Common mistakes
- Relying on referrers that email clients and the reader hide.
- Encoding a subscriber email or identity in UTM values.
- Using the same medium for emailed issues and web posts.
- Reusing one campaign value across multiple issues.
Privacy and accuracy notes
Use coarse labels such as utm_source=substack with utm_medium=email or referral. Never encode a subscriber email or identity in UTM values; they describe the campaign, not the reader.
Related pages
- Newsletter campaign tracking with UTM
Email clients usually send no web referrer, so newsletter clicks need UTM tags to be attributed at all. This page gives a recommended utm_medium=email structure with per-send utm_campaign naming, and the hard privacy rule that subscriber identifiers must never appear in a UTM.
- Medium campaign tracking with UTM
Medium articles can drive traffic through in-text links, author bios, and publication pages, and Medium routes outbound links through its own redirector. UTM parameters on the destination URL are the reliable way to attribute Medium traffic, provided the UTM survives the redirect to your landing page.
- Marketing vs transactional email UTM
Not every email is a campaign. Marketing sends belong in your UTM-tagged campaign reporting; transactional emails like receipts, password resets, and notifications do not. This page draws the line so functional clicks never inflate your marketing numbers.
- Campaign links docs
Unify Substack email and web clicks under one channel.
Sources and verification notes
- Substack — Sharing and links supportPosts delivered by email and web reader; referrers vary by surface.
Last reviewed 2026-06-24. Facts are checked against primary/official sources where available; uncertain specifics are marked “Data not yet verified” rather than guessed.