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, 4,000 for Verified subscribers, 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 and alt text

Attach up to 4 images or 1 video per tweet. Add alt text to each image to improve accessibility and reach, X surfaces alt-text-rich content in screen readers and visual search. 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.

Polls

Create polls directly from the Composer. Add 2 to 4 options and pick a duration (5 minutes to 7 days). posterly schedules the poll for the time you choose and publishes it natively through X's API at the scheduled moment.

Reply controls

Choose who can reply to each scheduled tweet: everyone, only people you follow, only people you mention, verified accounts, or your subscribers. Reply controls are set per-post in the Composer.

X Communities

X retired its Communities feature on 30 May 2026, citing very low usage and high spam, so posting to a community is no longer possible on X through posterly or any other tool. Schedule your posts to your main timeline instead, and use replies, quote posts, and threads to reach the same audience.

Writing for how X actually ranks content

The public xai-org/x-algorithm repository shows that For You ranking is built around predicted actions, not just likes. Useful signals include replies, reposts, quotes, profile clicks, link clicks, shares, follows, dwell time, video quality views, and media interactions. Negative signals include not-interested, mute, block, report, and low dwell.

posterly helps you schedule posts built for those actions: sharp first lines, reply prompts, screenshot or demo proof, quote-worthy takes, useful threads, and follow-up replies. The goal is not to fill a calendar with sentences. The goal is to publish posts that make the right audience stop, respond, click your profile, share, or follow.

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 can create tweet threads for longer-form content and help reframe winning posts with a fresh angle instead of copy-pasting the same thing until the feed learns to ignore it.

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.