--- title: "Tools for X: Character Counter, Thread Maker and More" description: "Tools for writing, planning and designing X posts: character counter, thread maker, best time planner, image sizes and more. All run in your browser." url: https://kairopost.com/tools --- 16 tools · no sign up # Tools for X Count characters the way X does, split threads, find the best time to post, size images and check links before you share them. Every tool runs in your browser, so nothing you type ever leaves your device. By Jonas Ben, founder of Kairo Post · Updated 30 September 2026 06 tools ## Write Get every post, thread and bio right before it goes out. - [X character counter Count characters exactly the way X does.](https://kairopost.com/tools/x-character-counter) - [Thread splitter Turn long text into a clean, numbered thread.](https://kairopost.com/tools/x-thread-splitter) - [AI phrase checker Spot the phrases that make writing sound machine made.](https://kairopost.com/tools/ai-phrase-checker) - [Hook grader Score your opening line against a clear checklist.](https://kairopost.com/tools/hook-grader) - [Bold and italic text Bold, italic and more, with an accessibility check.](https://kairopost.com/tools/x-text-formatter) - [Bio and alt text checker Check name, handle, bio and alt text limits.](https://kairopost.com/tools/x-bio-checker) 04 tools ## Plan Decide when to post, how often and whether it is working. - [Best time to post planner Find the hours when your audience is awake.](https://kairopost.com/tools/best-time-to-post) - [Engagement rate calculator Work out engagement rate the right way.](https://kairopost.com/tools/engagement-rate-calculator) - [Content calendar generator Plan a month of posts around your pillars.](https://kairopost.com/tools/content-calendar-generator) - [Duplicate post checker See how similar two drafts really are.](https://kairopost.com/tools/duplicate-post-checker) 03 tools ## Design Images, cards and previews that look right on X. - [Quote card maker Turn a line or headline into an image for X.](https://kairopost.com/tools/quote-card-maker) - [Image size guide and cropper Every X image size, with a cropper.](https://kairopost.com/tools/x-image-size-guide) - [Post preview See your draft as your followers will.](https://kairopost.com/tools/x-post-preview) 03 tools ## Build For developers wiring X and webhooks into their own tools. - [X API cost calculator Estimate API usage for your posting volume.](https://kairopost.com/tools/x-api-cost-calculator) - [UTM link builder Tag links so you know which posts drive visits.](https://kairopost.com/tools/utm-builder) - [Webhook signature verifier Check an HMAC SHA256 signature privately.](https://kairopost.com/tools/webhook-signature-verifier) ## Private by design The tools run on your device with no uploads, no AI calls and no connection to X. Close the tab and nothing remains. ## Built on X's rules Character weights, link lengths, image sizes and limits follow X's own documentation, with links to the source on each page. ## Kept current Each page shows who wrote it and when it last changed. When X changes a rule, the tool changes with it. ## When you are ready to stop doing it by hand Kairo Post counts, splits, designs, schedules and checks every post for you, across every account, in each account's own voice. You approve what goes out and see the price of every action first. [See all features](https://kairopost.com/features) [Use it from your AI assistant](https://kairopost.com/mcp) [Plans and pricing](https://kairopost.com/pricing) - Character counter and thread splitter [Composer and publishing](https://kairopost.com/features/publishing) - Best time planner and calendar [Scheduling](https://kairopost.com/features/scheduling) - Phrase checker and hook grader [AI writing and voice](https://kairopost.com/features/ai-writing) - Quote cards and image sizes [Images and media](https://kairopost.com/features/visuals) - Engagement rate and UTM links [Analytics](https://kairopost.com/features/analytics) - Webhook verifier and API costs [API and webhooks](https://kairopost.com/features/developers) ## About the tools ### Do the tools cost anything? No. There is no sign up, no trial and no limit on how often you use them. They run in your browser, so they cost us nothing to run. ### Is what I type stored anywhere? No. Every tool runs entirely on your device. Your text, images and numbers are never uploaded, and the tools make no calls to AI services or to X. ### Do the tools need an X account? No. None of them connect to X. They follow X's published rules, such as how characters are counted and which image sizes to use, so you can check your work before you post. ### Who makes these tools? Jonas Ben, the founder of Kairo Post. Each tool page shows when it was last updated, and we update them when X changes its rules. ### How do these relate to Kairo Post? Each tool does one job by hand. Kairo Post does the same jobs for you inside a full publishing workspace: it counts, splits, schedules, designs and checks posts automatically, with your approval before anything goes out. ### Can I suggest a tool? Yes. Write to support@kairopost.com with what you need and why. We build the ones that many people ask for. ## Post at the right moment. Starting today. Connect an account, describe your voice and let Kairo Post do the legwork. [Get started](https://app.kairopost.com/signup) [See pricing](https://kairopost.com/pricing)