Schedule Tweets & Threads with AI Assistance

Connecting your X account

Connect your X (formerly Twitter) account to posterly through the Accounts page. posterly uses X's official OAuth 2.0 flow to authenticate — you'll be redirected to X to approve access, then returned to posterly. The connection grants posting permissions only; posterly never reads your DMs or modifies your profile.

Scheduling tweets

Open the Composer, select your X account, and write your tweet. posterly shows a live character counter — X allows 280 characters for standard accounts and 25,000 for Premium subscribers. The AI can generate tweet-optimised captions that hit the right length and tone for the platform. Pick your date and time, or use "Next available" to find an open slot.

Posting with media

Attach up to 4 images or 1 video per tweet. posterly validates file sizes and formats against X's requirements automatically. Images can be JPEG, PNG, GIF, or WebP. Videos can be up to 140 seconds for standard accounts and longer for Premium users. Media is uploaded to X's servers at publish time.

Community posts

If you're a member of X Communities, posterly supports posting directly to a community. Add your community ID in the Community selector in the Composer. Note that X's API doesn't expose a list of your communities, so you'll need to enter the community ID manually (found in the community's URL on X).

AI-powered tweet writing

posterly's AI is tuned for X's short-form style. It generates punchy, concise tweets that drive engagement — no fluff, no filler. You can generate multiple variations and pick the one that fits your voice. The AI also suggests relevant hashtags and can create tweet threads for longer-form content.

Best times to post on X

Use the AI Agent to find optimal posting windows. X engagement patterns tend to peak during commute hours and lunch breaks, but the AI analyses your specific audience and posting history to give personalised recommendations.