Threads Character Limit: 500 Per Post, 10,000 Attached

X caps a post at a weighted 280 characters, with links and emoji priced differently, as set out in how X counts its 280. The Threads character limit is 500 per post, the figure Meta printed in its July 2023 launch post (“posts can be up to 500 characters long”) and still prints in its developer docs as of November 2026. The second Threads number in circulation, 10,000, is a different field: a text attachment, which adds longer text to a 500-character post.

• Post: 500 characters, with each emoji counted as its UTF-8 bytes (Meta’s API docs)
• Text attachment: up to 10,000 characters plus one link, on text-only posts (Meta’s API docs and newsroom)
• Links: 5 unique URLs per post; since 22 December 2025 the API rejects posts with more
• Topic tag: one per post, 1 to 50 characters

I treat a Threads limit as settled when a Meta page prints it, and on that test the list above holds, along with poll options, alt text, carousels and video length. The bio’s 150, the 30-character name fields and the 1,000-character DM that guides print fail it: none of the 10 Meta developer and newsroom pages I read on 5 November 2026 states them, so this post marks each one with the guide that does.

What Is the Threads Character Limit?

500 characters per text post. Meta’s Threads API overview, updated 22 December 2025, says under Other limitations: “Text posts are limited to 500 characters.” The Threads Posts page repeats it word for word under Limitations and adds: “Emojis are counted as the number of UTF-8 bytes.”

None of the Meta pages I read gives a word count. As a rough guide from this post’s own copy, the four bullets above hold 56 words in 318 characters, spaces included, which puts 500 characters near 88 words of similar English. Count characters, since that is what Meta limits.

Threads Limits by Field, and Who States Each One

Every row was read on 5 November 2026. “Meta API docs” means a page on developers.facebook.com, which describes what the Threads API accepts; for most of these fields no Meta page I read gives a separate figure for the app. “Guide only” means no Meta page I read states the figure.

UniLink also prints 1,000 for alt text, and on that field Meta agrees: the publishing reference says “The maximum length of alt_text is 1,000 characters.”

Does the 10,000-Character Text Attachment Replace the 500?

No. The post stays at 500 characters, and the 10,000 belongs to an attachment on it. Meta’s newsroom post of 4 September 2025 says “we’re rolling out a way to attach up to 10,000 characters of text to a post”, and the Text Attachments API page says they let you “share long-form writing in a post or a reply with up to 10,000 characters and a link.”

The rules on that API page:

• The plaintext field takes “a maximum of 10,000 characters.”
• “Text attachments can only be attached to text-only posts”, so no image, video or carousel.
• “Text attachments cannot be attached to a post that has a poll.”
• If the main post already has a link attachment, the text attachment cannot add its own.
• Styling covers bold, italic, highlight, underline and strikethrough.
• The 5-link cap applies across the post and its attachment.

Two pages misread the attachment in opposite directions:

t2online’s body has it both ways: its first line says “Users now have 10,000 characters to play around with when posting on Threads”, and its second describes the change correctly as letting users “append text snippets of up to 10,000 characters”. For a long take, write the hook in the 500 and the full text in the attachment, and keep the post text-only.

How Threads Counts Emoji Against the 500

Meta’s rule is one sentence on the Posts page and in the publishing reference: “For the post character limit, emojis are counted as the number of UTF-8 bytes.” Neither page gives a byte rule for anything other than emoji. For reference, these are the UTF-8 byte lengths Node 22’s Buffer.byteLength returned for this post:

Two cautions:

• UniLink says “Most emojis count as 1 character on Threads”, which does not match Meta’s byte rule.
• The words “number of UTF-8 bytes” on the Posts page link to grapheme-splitter on npm, a library its registry entry describes as breaking “strings into their individual user-perceived characters”. That library counts visible characters, so do not use it to count bytes.

Taras Shynkarenko’s AdaptlyPost guide works through a full post where emoji bytes push a draft past 500, if you want the arithmetic at post length.

How Many Links Can a Threads Post Have?

Five unique URLs. The Posts page says “The number of links is restricted to 5 or fewer”, and adds a dated warning: “Starting December 22, 2025, Threads posts containing more than 5 links will fail to post” with the error code THREADS_API__LINK_LIMIT_EXCEEDED.

Meta’s counting examples, from the same page:

The rules behind those rows: every unique URL in the text counts, a link attachment that differs from them counts as one more, and a repeated URL counts once. If you send no link_attachment, the first link in a text-only post becomes the preview card. Link attachments work on text-only posts, not on image, video or carousel posts.

Topic Tags and Polls on Threads

Topic tags, from the Posts page:

• “Topic tags must be at least 1 character and no more than 50 characters long.”
• “Only one topic tag is allowed per post”; through the API, the first valid in-text tag becomes the tag.
• Periods and ampersands are not allowed. In-text tags also end at a space, @, !, ?, comma, semicolon or colon.
• A hash sign before a whole number, such as #1, does not become a tag.

Threads takes one topic tag per post; an Instagram caption takes up to five hashtags, per the Instagram hashtag limit and its sources.

Polls, from the Polls page and the newsroom:

• “at least 2 options and no more than 4 options”
• “Each option must be between 1 and 25 characters long.”
• “You can attach polls only to text-only posts”, and a poll post cannot take a text attachment.
• The poll “will run for 24 hours”, per Meta’s 26 October 2023 newsroom update.

At 25 characters, a Threads poll option is shorter than YouTube’s text poll answers, which run to 65 in YouTube’s post image and poll specs.

Threads Bio Character Limit and Other Figures Meta Does Not Publish

The bio limit has no Meta source I could read. The pages I checked on 5 November 2026 were the API overview, Posts, Text Attachments, Polls, the publishing reference, Accessibility, Reply management, Create Replies and the 2023 and 2025 newsroom posts; none contains “bio” or “biography”. Meta’s Help Center article Edit your profile on Threads says in its page description that “You can update some of your profile information on Threads, including your bio, links and profile picture”, but its body did not load for a plain request, so I cannot say whether it states a number.

Notes on the table:

• Username: Meta’s 2023 launch post says “Your Instagram username and verification will carry over”, so the handle comes from Instagram. It gives no length.
• Reply: Meta’s Create Replies page creates a reply through the same POST /threads endpoint as a post, with a reply_to_id parameter, and states no separate character figure for it.
• Bio: writing to 150 is the safe choice while no Meta page settles it. For the same split on LinkedIn, see which LinkedIn limits LinkedIn itself states.

Threads Media and API Rate Limits

These come from the API overview and the Posts page. The media specs describe what the API accepts, and the rate limits are API limits (the overview’s wording is “250 API-published posts”).

LinkedIn’s image and video specs for a post are in my LinkedIn post size reference.

Recheck the Threads Character Limit Each Quarter

The dates on these pages show how often Threads rules move: Meta announced text attachments on 4 September 2025, updated that newsroom post on 22 October 2025, and the 5-link enforcement began on 22 December 2025, the date the API overview shows as its last update. Recheck the overview, the Posts page and the Text Attachments page each quarter, and retry the Help Center profile article until it loads.

On Meta’s own pages, the Threads character limit is 500 per post, with a 10,000-character attachment for anything longer, 5 links, one 50-character topic tag and 25-character poll options. Write your next bio to 150 and treat that number as a guide’s figure until Meta prints one.