Substack Notes vs. Bluesky: Which Should You Prioritize?

Published: September 2026

These two platforms get compared often because they both emerged as alternatives in the post-Twitter landscape, but they're built on fundamentally different architecture - one closed and algorithm-curated, one open and mostly chronological - and the numbers on each have moved in very different directions recently.

The scale gap, and where it's heading

The trajectories matter as much as the current numbers. Bluesky has roughly 46 million registered accounts, but active usage has fallen sharply - a 27% year-over-year decline in monthly active users, dropping from an average of about 22 million quarterly active users at the end of 2024 to under 11 million more recently, with around 10 million monthly and 3 million daily active users on its mobile app as of mid-2026 (Letters by Burk). Substack Notes, over the same general period, drove over 32 million free subscriptions and nearly 500,000 paid subscriptions in three months, and is currently the top source of subscriber growth for publishers on the platform. One platform is growing as a subscriber-acquisition channel; the other is shrinking as a general social network.

Architecture: closed and curated vs. open and chronological

Substack Notes runs on a closed, single-company platform, with Substack's own algorithm deciding what gets shown to whom - explicitly optimized to convert readers into subscribers, per Substack's own team. Bluesky runs on an open protocol (AT Protocol), with feeds that are mostly chronological by default, though customizable feed algorithms exist as an option users can choose into rather than a single company-controlled ranking. This is the core philosophical difference: Bluesky gives users more control over their own algorithm and data; Substack gives up that control in exchange for a feed specifically built to drive subscriptions.

Links: a real, concrete difference

One specific, measurable distinction: Bluesky does not penalize links in posts, while Substack's own algorithm has been reported to significantly suppress reach for Notes linking to external platforms - in some comparisons, Notes with off-platform links saw around 20 views versus 1,000+ for a comparable Note without one. This makes Bluesky a genuinely better fit if your Notes strategy leans heavily on linking out. A related, useful data point: publishers reportedly saw roughly 3x more click-through traffic from Bluesky than from Threads in a similar comparison, suggesting Bluesky's more permissive approach to links translates into real referral traffic, not just a policy difference on paper.

A quirk worth knowing about Substack's own feed

One specific criticism of Notes' algorithm: it reportedly favors content about Substack itself - Notes discussing the platform, growth tactics, or writing advice tend to get more algorithmic love than Notes on other topics, simply because that's a large share of what the power-user base (other writers) engages with most. This is worth knowing if your niche has nothing to do with writing or newsletters - you may be competing against a feed that's structurally biased toward meta-content about Substack, rather than a neutral playing field for any topic.

No hashtags on Notes - a smaller but real feature gap

Substack Notes doesn't support clickable hashtags by design, while Bluesky (like most social platforms) does. If discovery-by-topic-tag is part of how you'd normally reach new readers, that mechanism simply doesn't exist on Notes the way it does elsewhere.

The actual recommendation

For a newsletter writer specifically, the practical guidance is fairly clear: prioritize Substack Notes first. The audience there already has active Substack accounts and existing subscription behavior, meaning the path from seeing your Note to becoming a subscriber is short - often a single click, no new account needed. Bluesky is a reasonable secondary channel, particularly for driving external traffic via links (which Notes actively discourages), but its declining active-user base is a real factor to weigh against investing significant ongoing effort there.

Where Bluesky specifically helps

Despite the usage decline, Bluesky isn't nothing - it's described as a legitimate channel for indie writers, niche experts, and essayists specifically, and it can put your work in front of readers who'd genuinely never encounter you on Substack's own closed ecosystem otherwise. If you already have Notes as your primary channel and have spare capacity, cross-posting there (or repurposing your best Notes into Bluesky-native posts) is a reasonable low-cost addition - just not a substitute for Notes as the primary growth engine.

The bottom line

Substack Notes and Bluesky aren't really in the same category anymore in terms of trajectory - one is the platform's fastest-growing subscriber channel, the other is a shrinking general network with a more open, writer-friendly link policy. For subscriber growth specifically, Notes wins clearly. For external link-driven traffic and reaching readers who'll never open Substack directly, Bluesky remains a legitimate secondary option.

Whichever platforms you cross-post to, know exactly how your actual Substack Notes are performing. NotesIQ tracks your real engagement and growth automatically.