Threads posts have a 500 character limit for the main text, with replies also capped at 500 characters. However, the platform introduced text attachments in September 2025 that allow up to 10,000 characters—displayed as a separate expandable section that doesn’t count toward your main 500. The key advantage: Threads’ 10,000-character text attachments are FREE, unlike X Premium’s 25,000-character posts which require a paid subscription. This positions Threads as a compelling alternative for long-form content.

This guide covers all Threads character limits and strategies for Meta’s fast-growing Twitter alternative.

Threads Character Limits Overview

Key comparison: Threads 500 (+10K free) vs X/Twitter 280 (25K paid Premium)

Main Post Limits (500 Characters)

The 500 Character Limit

What counts:

• All text including spaces
• Emojis (typically 2 characters each)
• Line breaks

What doesn’t count:

• Text attachments (separate 10,000 limit)
• Images and videos (up to 10-20 per post)
• Link preview cards (link text still counts)

Comparison to Twitter/X

Threads (500 chars + 10K free) vs Twitter/X (280 chars or 25K paid):

• Nearly double the base space
• Room for more context
• Free long-form option (vs paid X Premium)
• Still encourages brevity for main posts

Best performing Threads content: Research suggests shorter posts (1-2 lines) often perform best, despite the higher limit.

Optimal Post Length

Engagement patterns:

• 1-2 lines: Highest engagement for quick thoughts
• 200-300 chars: Good for developed ideas
• 400-500 chars: Use when topic requires it

Recommendation: Don’t feel obligated to use all 500 characters. Let content determine length.

Text Attachments (10,000 Characters)

What Text Attachments Are

Added September 2025: Feature allowing long-form text separate from main post

Key advantage: 10,000-character text attachments are FREE (unlike X Premium’s 25,000-character posts which require payment)

How it works:

1. Write your main post (up to 500 chars)
2. Add text attachment for extended content
3. Attachment appears as expandable section
4. Doesn’t count toward 500-character main limit
5. Includes bold, italic, and underline formatting

When to Use Text Attachments

Good uses:

• Essays or detailed thoughts
• Lists that exceed 500 characters
• Full context that doesn’t fit main post
• Stories or long-form narratives

Strategic approach:

• Main post: Hook and key point
• Attachment: Full context for those who want it

Text Attachment Best Practices

Hook must work standalone: Main post should make sense even if attachment isn’t read.

Format for readability:

• Use line breaks
• Create sections
• Keep paragraphs short

Replies (500 Characters)

Reply Limits

Same as posts: 500 characters per reply

Threads allow:

• Replies to posts
• Replies to replies
• Quoted replies

Reply Strategy

For engagement:

• Add value with replies
• Build on original post’s point
• Ask follow-up questions

Character efficiency: 500 characters is sufficient for most conversational replies.

Profile and Bio (150 Characters)

Bio Limit

Maximum: 150 characters (synced with Instagram)

Bio Optimization

Threads-Instagram connection:

• Threads profile pulls from Instagram
• Changes to one may affect the other
• Consider both platforms when writing bio

What to include:

• What you share about
• Personality or unique angle
• Call-to-action if relevant

Media Attachments

What You Can Attach

Per post:

• Up to 10 images (expanded to 20 for some users)
• Videos up to 5 minutes
• Mixed media combinations

Format consideration: Media doesn’t use character count but affects post appearance.

Cross-Posting to Instagram

The Feature

Available option: Share Threads posts to Instagram feed

How it works:

• Option appears when posting
• Threads content appears as Instagram post
• Character limits still apply to original

Strategy Considerations

When to cross-post:

• Content fits both audiences
• Visual content that works on Instagram
• Announcements reaching both communities

When not to:

• Threads-specific conversations
• Reply threads
• Very text-heavy content

Threads vs. Other Platforms

Character Comparison

Platform Positioning

Threads sits between:

• Twitter’s quick takes
• Instagram’s visual focus
• LinkedIn’s professional depth

Content that works:

• Conversational thoughts
• Hot takes and opinions
• Quick updates
• Community engagement

Engagement on Threads

What Performs Well

Early platform data suggests:

• Authentic, conversational content
• Opinions and takes
• Short, punchy posts (1-2 lines)
• Questions and engagement prompts
• Text over heavy multimedia

Building Presence

Platform tips:

• Engage with others’ posts
• Reply thoughtfully
• Post consistently
• Cross-promote from Instagram

Frequently Asked Questions

Is the 500 character limit enough?

For most content, yes. Text attachments provide overflow space when needed. Most viral Threads are shorter than 500 characters.

Do links count toward the character limit?

Yes, link text counts toward your 500 characters. Link preview cards display separately.

Can I edit Threads posts after publishing?

Yes, Threads allows post editing after publication.

Does Threads have hashtags?

Threads has limited hashtag functionality compared to Instagram. Using a few relevant hashtags may help discoverability.

How is the Threads algorithm different from Twitter?

Threads emphasizes showing content from followed accounts while mixing in recommended content. The exact algorithm isn’t publicly documented.

Will Threads character limits change?

Possible. Twitter started at 140 and expanded to 280. Meta may adjust limits as the platform evolves.

Key Takeaways

• Threads posts: 500 characters maximum
• Text attachments: 10,000 characters for long-form content (FREE, Sept 2025)
• Replies: 500 characters
• Bio: 150 characters (linked to Instagram)
• Media per post: 10-20 items
• Text attachments include bold, italic, underline formatting
• Key advantage: 10K free text attachments vs X’s 25K paid
• Shorter posts (1-2 lines) often perform best
• Cross-posting to Instagram is available

Conclusion

Threads offers more breathing room than Twitter with its 500-character limit, plus the unique text attachment feature for long-form content. However, engagement data suggests that shorter, punchier content often performs best—the limit is a ceiling, not a target. Use the full space when your content requires it, but don’t pad posts just because you can. Try our free letter counter → to verify your Threads content fits within platform limits.