How to post to Bluesky and Instagram at the same time

The six differences that matter

Those are the platforms’ own rules as Bloom applies them on 2 October 2026. Everything below follows from them.

Write the post for Instagram, then cut a Bluesky version

Start with the long one. Instagram gives you room for the story, the credits, the hashtags. Then write the first sentence as if it were the whole post, because on Bluesky it nearly is: 300 characters is roughly two short sentences and a link.

A workable pattern:

• Line one says the thing. Under 200 characters so it survives Bluesky with room for a link.
• Lines two onward carry the detail for Instagram: context, who is in the photo, where, the alt text if the platform lets you add it.
• Hashtags go at the end on Instagram. On Bluesky, hashtags are clickable but the culture is a few at most; one or two is plenty.

In Bloom you write the long version once and it is fitted to each platform’s length when it publishes, so a Bluesky version that stands on its first sentence survives the cut. Nothing is generated for you; it is your sentence, shortened by you.

Links: the biggest difference

On Bluesky a URL in the text becomes a clickable link and, usually, a preview card. On Instagram a URL in a caption is just text; nobody can tap it. So a post that says “new video, link below” works on Bluesky and strands people on Instagram.

The fix is to let the two versions differ in exactly one place. Bluesky gets the URL. Instagram gets “link in bio” and the link really is in your bio, or in a link-in-bio page you keep current. If you use a tool that posts the same text to both, strip the URL for Instagram; if your tool fits the post per platform, as Bloom does, keep the URL in the Bluesky version and drop it from the Instagram caption.

Photos, carousels and video

Up to four photos work on both. Five to ten photos post as a carousel on Instagram; Bluesky takes the first four. If the order matters, put the four that stand alone first.

Video is where the two diverge. A single video goes to Instagram as a Reel and to Bluesky as a video post. A video mixed with photos becomes a carousel item on Instagram, but Bluesky posts carry one video or up to four photos, never both, so the Bluesky version will be the video alone or the photos alone. Decide which you want before you schedule, rather than discovering it afterwards.

File sizes depend on your plan: Bloom’s free plan takes files up to 25MB, Pro and Plus up to 500MB, and each platform then applies its own limits.

Connecting the two accounts

Bluesky connects with an app password you create in Bluesky’s settings. It is not your main password, and you can revoke it from Bluesky at any time without changing anything else.

Instagram connects through Meta’s own sign-in and needs a professional account (Business or Creator). Bloom is approved by Meta for publishing, and the connection asks only for the permissions it uses.

Schedule once, check twice

Pick a time that suits both audiences. If they keep very different hours, schedule the post twice, once for each platform; a scheduler does not force the same minute on both. If you have logged results for a few weeks, the best-time view will show whether your Bluesky and Instagram audiences keep different hours.

After the first few cross-posts, open both platforms and look. Is the Bluesky text cut mid-thought? Did the Instagram caption say “link below”? Does the fourth photo on Bluesky make sense without the fifth? Fix the pattern, not the post, and the next month is automatic. See how cross-posting works for the per-platform fitting Bloom does.

Frequently asked questions