X is still larger, though it no longer publishes a figure to prove it. Bluesky is smaller, growing, and by a wide margin the easier of the two to build on: its API is open, free and has no review queue. Which one you should use depends almost entirely on whether your audience is technical.
How big is each?
Bluesky’s own company blog said it had grown to over 43 million global users as of July 2026. That is registered accounts, not monthly actives, and the two are very different metrics.
X has not published user numbers since it went private. Every current figure in circulation is a third-party estimate. We are not printing one here as though it were disclosed.
| Bluesky | X | |
|---|---|---|
| Audience | Over 43 million registered accounts (Bluesky, July 2026) | Not published since the company went private |
| Post length | 300 characters | 280 characters, more for paid accounts |
| Media | Images and video | Images and video, longer limits when paid |
| Feed control | Custom feeds, pick or build your own algorithm | One algorithmic timeline, plus a chronological view |
| API for posting | AT Protocol, open and free, no app review | Paid access tiers, minimal free tier |
| Account portability | Yes, self-hostable data server and portable handle | No |
| Monetisation | None built in | Ads revenue share for paid subscribers |
| Suits | Tech, journalism, science, open-source | Real-time news, mass reach, existing followings |
Note: Figures here were verified against Bluesky’s own company blog (July 2026) and each platform’s published developer documentation and help centre as of September 2026. Platforms change these without notice.
Is Bluesky’s smaller audience actually a problem?
Less than the raw number suggests, and here is the honest version of why.
Bluesky’s population skews heavily towards technology, journalism, science and open-source communities. If that is who you sell to, the effective audience is far larger than 43 million divided by the internet. If you sell to a general consumer audience, it is much smaller, and the number is the number.
The other half of the answer is that engagement per follower on Bluesky has generally been better than on X for accounts that post regularly, which is what you would expect from a younger network with a less saturated feed. That advantage narrows as a platform grows, so do not build a strategy that depends on it lasting.
Which has the better API?
Bluesky, and it is not close for a developer.
The AT Protocol is public. You create a session, upload an image blob, and write a record. There is no app review, no business verification, no waiting on a queue, and no fee. You can run your own data server if you want to. The one genuine annoyance is that links and mentions are not auto-detected: they are declared as facets with byte offsets over the UTF-8 encoding of the text, which trips up nearly every first integration. We walk through it in the Bluesky API post tutorial.
X sells API access in tiers, with a free tier that is really a testing allowance. That is a legitimate business decision and it is also a hard constraint on anything you were planning to automate. Our summary of what the official documentation actually states is in X API pricing and limits.
What about custom feeds?
This is Bluesky’s one genuinely distinct feature, and it is worth understanding even if you never build one.
On Bluesky, the ranking algorithm is not a single thing the company controls. Anyone can publish a feed generator, and users subscribe to feeds the way they subscribe to accounts. In practice that means niche communities can build a feed that surfaces their own topic, and being included in a well-subscribed feed matters more than the follower count.
X has one main algorithmic timeline. You cannot opt into somebody else’s ranking, and you cannot build one.
Moderation and risk
Both platforms have been through public moderation controversies and both will again. The structural difference is that Bluesky supports stackable labelling services, so moderation is partly composable rather than a single centrally imposed policy, and account portability means being removed from one host does not have to mean losing your handle and followers.
For a brand, the practical question is simpler than the philosophy: how much of your audience relationship would you lose tomorrow if the platform changed its mind about you? On X the answer is all of it. On Bluesky it is less, though not zero.
Should you post to both?
Yes, and it is cheap to do. Both are text-first with similar limits, so one post usually fits both. Write to 280 characters and it will pass on both networks without editing.
The practical guide, including the facet problem that makes links look broken when you cross-post naively, is in cross-posting from X to Bluesky. Check your draft against the tighter ceiling with the X character counter.
The verdict: who should pick which?
Pick Bluesky if your audience is technical, or if you are a developer. Tech, science, journalism and open-source people are disproportionately there, the API is free and open, and custom feeds give a small account a route to the right readers that follower count alone would not.
Pick X if you need mass reach or real-time relevance. It is still bigger, and it is still where a breaking story gets discussed first. For news, sport, finance and politics that is decisive.
Keep X if you already have an audience there. Followers built over years do not transfer, and abandoning them to make a point is an expensive gesture.
Post to both if you post text. The marginal cost is close to zero and the two audiences overlap less than you would think.
The short version
Bluesky has over 43 million registered accounts, an open free API with no review, custom feeds, and an audience that skews technical. X is larger but no longer publishes figures, charges for API access, and remains the default for real-time news. Neither wins outright. Post to both if your content is text, and pick based on whether your buyers are technical.
Scheduling both without duplicate work
BulkPublish publishes to Bluesky and X alongside 13 other networks. Bluesky facets for links and mentions are generated for you, which removes the single most common cross-posting bug, and per-platform overrides handle the places where the two limits differ. See scheduling.