Thread maker for X, Threads, Bluesky and Mastodon
Paste long text and get a thread that fits. Each part stays inside the network's limit, ends where a paragraph or sentence does, and keeps its links whole. Number the parts, fix any of them by hand, and copy them one at a time.
Runs in your browser. Your text and images never leave it.
Updated
Split for
Each part fits 280, weighted: a link counts 23, and emoji and CJK characters 2.
Premium posts go up to 25,000, so a long text may fit in one post.
The number goes at the end of each part, and its room is kept in every part's count.
A common way to say there's more below. It counts toward the first part.
Your thread
Nothing to split yet
Your thread shows up here, one post under the other, as soon as there's text to split.
How threads work on each network
A thread is the same idea everywhere: your own posts, each one a reply to the one before. What differs is who can reply and who sees the rest.
X
On X, a thread is a run of your own posts, each one replying to the last. You build it in the composer with the plus button and post it all at once, or add a post to it later from the thread itself.
Reply settings let you limit who can answer, for example to accounts you follow or accounts you mention.
Sources: X Help Center: How to create a thread on X; X API: Create Post (reply and reply_settings)
Threads
On Threads, a thread is your post with your own replies chained under it. In Meta's API, each part is a reply to the part before it, made with reply_to_id.
Who can reply is set per post with reply_control: everyone, accounts you follow, people you mention, your followers, or only you.
Sources: Threads API docs: Create replies (reply_to_id); Threads API docs: Reply management (reply_control)
Bluesky
On Bluesky, every reply points at two posts: the first post of the thread, called its root, and the post it answers, its parent. Your thread is a chain of your own replies back to your root.
Reply settings live on that first post as a thread gate, and they cover the whole thread. You can let in people you mention, people you follow, your followers or a list, or nobody at all.
Sources: Bluesky lexicon app.bsky.feed.post: a reply points to its root and its parent; Bluesky lexicon app.bsky.feed.threadgate: reply controls live on the thread's first post; Bluesky docs: Thread gates
Mastodon
On Mastodon, a thread is a chain of your posts, each one replying to the last. Every post has its own visibility: Public, Quiet public, Followers or Private mention.
A reply reaches a follower's home feed only if they follow both people in it. When you reply to yourself, that's just you, so your followers see each part.
Our suggestion: post the first part as Public and the rest as Quiet public. Quiet public posts stay out of the live feeds, explore and search, so the follow-ups don't crowd them.
Sources: Mastodon docs: Posting (visibility, replies, content warnings); Mastodon API: Post a new status (in_reply_to_id, visibility)
How long each part can be
Each part is a post of its own, so each has the network's full limit. The catch is that every network counts a little differently.
| Network | Each part | How it counts | A link costs | Numbering takes |
|---|---|---|---|---|
| X | 28025,000 with Premium | Weighted: most letters 1, emoji and CJK characters 2 | 23, however long it is | 5for "3/12" |
| Threads | 500up to 5 different links | As the app counts: most emoji take 2 | Every character, as typed | 5for "3/12" |
| Bluesky | 300and 3,000 bytes | Characters as you see them: an emoji is 1 | Its address and the first 13 characters of its path, then "..." | 5for "3/12" |
| Mastodon | 500unless your server sets its own | Characters as you see them, content warning included | 23, however long it is | 5for "3/12" |
Numbering and the thread emoji come out of that room too. This tool keeps it free in every part before it splits, so a part that fits here still fits with its number on the end.
Bluesky's count assumes the app's link shortening. If you post through the API, links count in full: turn off link shortening above and the thread splits for that.
Should you number the parts?
Our take: number a thread of four or more parts, and leave a short one as it is.
Numbers tell a reader how long the thread is and where they are in it. That matters most when someone lands in the middle, from a reply or a share, and wants to know if there's more.
They also cost room. A number like "3/12" takes 5 of every part on X, and the 🧵 takes 3 more on the first. That's 5 of 280 on each X post: little on its own, but over twelve parts it adds up to a sentence or two.
Writing the total means knowing the length before you post. This tool knows it, so it writes it, and it widens the room when a thread grows from 9 parts to 10.
The 🧵 on the first part is a common way to say there's more below. Screen readers say it as "thread", so it reads as a word, not decoration.
Write a first part that earns the rest
Most people decide from the first post whether to read on. These are our habits, not a network's rules.
- Lead with the point. Say what you found or what you think first. The setup can come in part two.
- Make it whole on its own. Someone who reads only the first post should still take something away.
- Say what's coming. "Five things I'd change" tells people the size of what they're starting, and the numbering keeps the promise.
- Keep links lower down. A first post that's mostly a link reads like an ad. Put sources in the parts they back up, or at the end.
- Read it out of order. Open part four on its own. If it needs part three to make sense, add a few words of context.
Can Shaflex split a thread for me?
Yes. In Shaflex you write one draft and pick your channels, and Split automatically turns a long draft into a thread that fits each network you picked, for X, Threads, Bluesky and Mastodon at once. You can still edit any part.
When the time you scheduled comes, Shaflex posts the first part and then each next part as a reply to the one before.
The composer splits with its own rules, so its parts won't always break where this tool's do. Check the parts there before you schedule.
See how Shaflex schedules for X, Threads, Bluesky and Mastodon, how one draft goes to every network, and what the free plan includes.
Where these rules come from
Each one is from the network's own documentation, help pages or source code. We last checked them on .
- X Help Center: How to create a thread on X
- X API: Create Post (reply and reply_settings)
- Threads API docs: Create replies (reply_to_id)
- Threads API docs: Reply management (reply_control)
- Bluesky lexicon app.bsky.feed.post: a reply points to its root and its parent
- Bluesky lexicon app.bsky.feed.threadgate: reply controls live on the thread's first post
- Bluesky docs: Thread gates
- Mastodon docs: Posting (visibility, replies, content warnings)
- Mastodon API: Post a new status (in_reply_to_id, visibility)
- X developer docs: Counting characters
- twitter-text config v3: character weights and link length
- X Help Center: X Premium, longer posts
- Threads API docs: Posts (500 characters, emoji, 5 links, topic tags)
- Bluesky app source: toShortUrl
- Bluesky app source: shortenLinks
- Mastodon source: StatusLengthValidator
- Mastodon API docs: GET /api/v2/instance
- Mastodon source: the instance configuration it publishes
More free tools
Each one runs in your browser too.
- Text tool
Character counter
Count one draft for Threads, X, Bluesky, Mastodon and LinkedIn at once, and cut it to fit.
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Character limits, every network
Every limit for the five networks: what counts as a character, what a link costs, the source and the day we checked.
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Invisible character remover
Find the zero-width spaces, stray joiners and styled letters hiding in a draft, see where each one sits and what it costs on each network, and take them out without breaking an emoji.
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Questions
How long can each part of a thread be?
As long as one post on that network: 280 on X (25,000 with Premium), 500 on Threads, 300 on Bluesky, and 500 on Mastodon unless your server sets its own. Numbering takes a few of those characters in every part, and this tool keeps that room free.
Does the thread maker post for me?
No. It splits and numbers your text, and you copy each part into the app yourself. To schedule a thread instead, Shaflex posts the first part and each next one as a reply to the one before.
Will a link get cut in half?
No, unless that one link is longer than a whole post. Links are counted the way each network counts them: 23 on X and 23 on Mastodon whatever their length, shortened on Bluesky, and as typed on Threads.
Why does an X part end well before 280 letters?
Because X weighs characters. Most letters count 1, but emoji and Chinese, Japanese and Korean characters count 2, and every link counts 23. A part full of emoji or CJK text holds about half as many characters.
Can I make a thread for LinkedIn?
No, LinkedIn doesn't have threads. A LinkedIn post holds up to 3,000 characters, so text that needs a thread elsewhere often fits in one post there.
Is my text saved or sent anywhere?
No. The split runs in your browser, and your text isn't stored or sent. The one request the tool makes is to your Mastodon server, with just the server's name, when you type one in.
Write the next post once.
Shaflex fits it to Threads, X, Bluesky, Mastodon and LinkedIn, schedules it on your rhythm and brings the replies back to you.
Free plan, no card needed.