Compose once. See every platform. Ship without surprises.

A focused composer with live previews for every platform you post to. Image crops, line breaks, link cards, hashtag spacing, all rendered the way each platform actually shows them. You fix the awkward stuff here, not in your followers' feeds.

Live previews for X, LinkedIn, Instagram, and 28 more
What you see in preview is what ships
Per-platform overrides without leaving the composer
Drafts auto-save every keystroke
See what your followers will see

Type on the left. Watch every platform render on the right.

One draft, live preview cards per platform. Catch the truncated line break, the bad image crop, the orphan hashtag, before they ship.

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Solo founder tip: stop launching on Tuesday. Talk to 5 customers this week. Write down the exact words they use. That's your roadmap.
#buildinpublic #solofounder #saas
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FoPost@owlstack

Solo founder tip: stop launching on Tuesday. Talk to 5 customers this week. Write down the exact words they use. That's your roadmap. #buildinpublic

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FoPostSolo-founder social tooling · Now

Solo founder tip: stop launching on Tuesday. Talk to 5 customers this week. Write down the exact words they use. That's your roadmap. The next 5 features you ship should come from the last 5 customer conversations you had. #buildinpublic #solofounder #saas

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owlstack

Solo founder tip: stop launching on Tuesday. Talk to 5 customers this week. Write down the words they use. That's your roadmap. The next 5 features write themselves. #buildinpublic #solofounder

Pixel-accurate previews
Updates live as you type
Fix here, not in feeds
The cost of blind posting

Most of your weird posts came from never previewing.

Your photo looks great on Instagram. On X, the auto-crop chopped your face out. You found out from the screenshot a friend sent that night.

The 4-line breakdown that made your tweet land became one big paragraph on LinkedIn. The post is technically there. Nobody read past line 3.

The link preview that unfurled beautifully on Slack just shows as a raw URL on Bluesky. You meant for that headline to do the work. It is doing none of the work.

Is this for you?

Is the composer for you?

For you if

  • You ship to 2+ platforms and want to see every render before pressing post
  • You have lost a post to a bad image crop or a broken line break (everyone has)
  • You write your social posts in Notion or Apple Notes today, copy them in, and want a real editor
  • You ship media-heavy posts and the auto-resize alone is worth the switch

Not for you if

  • You only post to one platform from that platform's app. The native composer is fine.
  • You publish from your own code via the API. The composer is for humans, not for scripts. (We have an SDK for that.)
What's inside

Built for shipping, not just typing.

Every detail of the composer was designed for the moment between writing the post and pressing the button.

Live previews per platform

X, LinkedIn, Instagram, Threads, Bluesky, and 26 more. Each preview matches the platform's actual render. Image crops, line breaks, link cards, "see more" cutoffs, hashtag color, all of it.

Per-platform overrides on the same screen

Tweak the caption for X without breaking LinkedIn. Drop a hashtag on Instagram, keep it on Threads. Every override is one click into the preview card. No tab switching.

Drag, drop, auto-crop

Photos, videos, GIFs, up to 50 MB and five files a post. Still images are framed for the platform they ship to: 1080×1080 Instagram, 1200×630 LinkedIn, 1600×900 X, 1000×1500 Pinterest, 1080×1920 TikTok. Video and GIFs publish exactly as you uploaded them.

Hashtags that fit the platform

AI-suggested hashtags ranked for your post and the platform you are shipping to. X loves 1-2, LinkedIn tolerates 3-5, Instagram lives on 8-12. The composer knows.

Spell check before your audience does

Your browser's own spell checker runs inside the editor, on by default, so the typo your eye skips gets the red underline. It covers whatever languages your browser already knows. One toolbar toggle turns it off when you are writing in something it will fight you on.

Drafts that never disappear

Every keystroke saves. Close the tab, your laptop dies, your kid hits the keyboard, the draft is still there when you come back.

How it works

Type. Preview. Ship.

01

Type once

Open the composer. Write the post the way you want it to read on the platform that matters most. Add hashtags and media.

02

Watch the previews

Every platform you have connected renders live on the right side as you type. You see the same post the way your followers will, on every network you are shipping to.

03

Fix what looks weird

Truncated line break on LinkedIn. Hashtag drowning the X version. Image cropping your face on Instagram. Click into any preview to override that one platform without touching the rest.

04

Ship or schedule

One click posts to every connected network at once. Or hand the post to the calendar, pick a time, and let the queue ship it.

vs the alternatives

Why this beats the platform-by-platform tour.

Three ways solo founders compose posts today. Only one of them shows you what you are about to ship.

Native composers, platform by platform

What most founders do

  • Type the post in Notes, copy it into X, edit it, post.
  • Copy it into LinkedIn, reformat the line breaks, post.
  • Copy it into Instagram, swap the image, write a caption, post.
  • Total: 20 minutes for one post on 3 platforms. Image crops still surprise you.

Buffer or Hootsuite composer

What most schedulers offer

  • One text area for all platforms. No live render per platform.
  • Previews are static cards, not the actual platform style.
  • Per-platform overrides are buried behind a dropdown.
  • You find out the image was wrong from the live post.
FoPost

FoPost composer

What you actually want

  • Live previews for every platform as you type.
  • Per-platform overrides on the same screen, no tab switching.
  • Auto-resize frames your images for the platform they ship to.
  • Ship or schedule from the same screen. One click.

Publishes to all major networks

Frequently asked questions

Does the preview match what actually publishes?

Yes. Each preview is rendered using the platform's own public template and CSS reference, refreshed when those platforms update. The only differences are platform-side personalization we cannot replicate locally, like X's "show this thread" UI or Instagram's "suggested for you" interleave.

Can I write in Markdown?

Yes. The composer supports Markdown shortcuts (**bold**, _italic_, > quote, - list) and converts them to whatever each platform accepts on publish. LinkedIn supports light formatting, X strips it, Instagram does its own thing. The composer handles each.

Can I override one platform without changing the others?

Yes. Click into any preview card to edit just that platform's version. Drop a hashtag, swap an image, change a hook. The other platforms keep your original draft. This is the per-platform overrides feature, built into the composer instead of buried elsewhere.

Does it work on mobile?

Yes. The composer is fully responsive. On phones, the previews stack below the editor instead of beside it, so you can swipe through each platform. A native mobile app is on the roadmap.

Can I save templates?

Yes. Save any post as a template, reuse with one click. Useful for product launches, weekly updates, newsletter announcements, anything you ship in a recurring shape.

How does AI rewriting work with the composer?

Hit the AI rewrite button and the composer drafts a per-platform version of your post directly inside the preview cards (using AI credits). You see all of them side by side, edit any, ship from there. The composer and the AI rewriter are the same surface.

What about video?

Videos render in the previews with thumbnail and runtime, and publish exactly as you uploaded them. Auto-resize applies to still images only, so nothing gets re-encoded behind your back. Upload the aspect ratio the platform expects: 9:16 for Reels and TikTok, 1:1 for the Instagram feed, 16:9 for YouTube and LinkedIn.

Does it support scheduling?

Yes. The composer's "Schedule" button hands the post off to the content calendar. You pick a time, the post is queued, you see it on the calendar with the same per-platform overrides you set in the composer.

Ready to try content composer?

7-day free trial. 30 platforms. Unlimited posts on every plan.