Getting your Reddit ad specs right is essential for campaign success. Improperly sized creative gets cropped, distorted, or rejected—wasting time and hurting performance. This guide covers every Reddit ad format's dimensions, file requirements, and character limits for 2026.

Bookmark this page as your quick reference for all Reddit advertising specifications.

Reddit Ad Formats Overview

Reddit offers several ad formats, each with specific creative requirements:

Image Ad Specs

Image ads are the most common Reddit ad format. Here are the complete specifications:

Image Dimensions

Reddit supports multiple aspect ratios for image ads:

Recommended: 4:5 portrait or 1:1 square ratios perform best on mobile, where 70%+ of Reddit usage occurs.

Image File Requirements

Image Ad Text Requirements

Best practice: Keep headlines under 100 characters to ensure full visibility across all placements.

Video Ad Specs

Video ads on Reddit are highly engaging and support a range of formats. Understanding reddit video ads specifications ensures your content displays perfectly across all placements.

Video Dimensions

Video File Requirements

Video Duration

Best practice: Front-load your key message in the first 3 seconds. Most users scroll quickly, so hook attention immediately.

Video Thumbnail Specs

Thumbnails display before autoplay and when users have autoplay disabled. Always upload a custom thumbnail rather than relying on auto-generated frames.

Video Ad Text Requirements

Carousel Ad Specs

Carousel ads let you showcase multiple images in a swipeable format:

Carousel Structure

Carousel Image Specs (Per Card)

Carousel Text Requirements

Best practice: Use carousel ads to tell a sequential story, showcase product features, or display multiple products. Maintain visual consistency across all cards.

Conversation Ad Specs

Conversation ads appear within comment threads, providing native placement. Learning best reddit conversation ads techniques helps maximize engagement with this format.

Conversation Ad Requirements

Conversation Ad Best Practices

• Shorter headlines required: 100 characters max (vs. 150 for feed)
• Native tone: Content should feel like part of the discussion
• Enable comments strategically: Be prepared to engage with responses
• Educational content wins: Users in threads expect helpful information

Conversation ads work exceptionally well when your content genuinely adds value to the discussion topic.

Text & Headline Requirements

Across all ad formats, these text specifications apply:

Character Limits Summary

Available Call-to-Action Buttons

Reddit offers these CTA options:

• Learn More
• Shop Now
• Sign Up
• Download
• Apply Now
• Contact Us
• Get Quote
• Watch More
• See Menu
• Book Now
• Play Now

Headline Writing Tips

1. Include your primary keyword naturally
2. Lead with value proposition or hook
3. Avoid excessive caps or punctuation!!!
4. Match community tone—corporate speak underperforms
5. Test multiple headlines (3-5 variants recommended)

Best Practices for Each Format

Image Ads

When planning your image creative, consider these approaches alongside your overall reddit advertising strategy to ensure format specs align with campaign goals.

Do:

• Use 4:5 portrait for mobile-first campaigns
• Add text overlay to images (but keep it minimal)
• Test meme-style creative against polished assets
• Include your logo subtly

Don't:

• Use heavy text overlays (reduces performance)
• Upload blurry or low-resolution images
• Use generic stock photos without customization
• Ignore aspect ratio recommendations

Video Ads

Do:

• Design for sound-off viewing (add captions)
• Hook viewers in the first 3 seconds
• Show actual product/service in action
• Keep optimal length around 60 seconds
• Use custom thumbnails

Don't:

• Start with logo animations (users scroll past)
• Rely on audio for key messaging
• Upload videos over 512 MB (slower processing)
• Use horizontal-only for mobile campaigns

Carousel Ads

Do:

• Tell a story across cards
• Use first card as the hook
• Maintain visual consistency
• Include CTA on final card

Don't:

• Mix aspect ratios across cards
• Use unrelated images
• Skip the narrative opportunity
• Overload with text per card

Conversation Ads

Do:

• Match the discussion topic authentically
• Prepare for user engagement (comments)
• Use educational/helpful content
• Keep headlines under 100 characters

Don't:

• Use aggressive sales language
• Ignore user comments
• Place in irrelevant threads
• Copy/paste feed ad content

Mobile vs. Desktop Considerations

Understanding device distribution is crucial for creative decisions. Many digital marketing agency reddit teams prioritize mobile optimization given platform usage patterns.

Mobile-First Design Tips

• Assume sound-off viewing
• Use larger text overlays (readable at small sizes)
• Keep key content in center safe zone
• Test thumbnails at mobile preview size
• Front-load messaging (users scroll quickly)

Quick Reference Cheat Sheet

Copy this table for your creative team:

Image Ads Quick Specs

Dimensions: 1080×1080 (1:1), 1080×1350 (4:5), 1920×1080 (16:9)
File type: JPG, PNG
Max size: 3 MB
Headline: 150 chars (feed), 100 chars (conversation)

Dimensions: Same as image (1080×1080, 1080×1350, etc.)
File type: MP4, MOV
Max size: 1 GB (recommended under 512 MB)
Duration: 5-60 seconds recommended (max 15 min)
Frame rate: 30 FPS
Thumbnail: 400×300 px, JPG/PNG, max 500 KB

Cards: 2-6 per ad
Dimensions: Same as image ads
File type: JPG, PNG
Max size: 3 MB per card
All cards: Same aspect ratio required

Frequently Asked Questions

What's the best image size for Reddit ads?

For most campaigns, use 1080×1350 pixels (4:5 portrait) for mobile-first reach, or 1080×1080 pixels (1:1 square) for balanced mobile/desktop performance. These dimensions work well given that 70%+ of Reddit usage is mobile. Understanding reddit advertising targeting options helps determine which format best reaches your audience.

What video length works best on Reddit?

While Reddit allows videos up to 15 minutes, the optimal length is 60 seconds for engagement metrics. For awareness campaigns, 15-30 seconds works well. Always hook viewers in the first 3 seconds. Review reddit ads examples to see how top performers structure their video content.

Can I use GIFs in Reddit ads?

Reddit accepts GIF files, but they get converted to static images. If you want animated content, use MP4 video format instead.

What's the maximum file size for Reddit ads?

Image ads: 3 MB maximum. Video ads: 1 GB maximum (512 MB recommended for faster processing). Carousel cards: 3 MB per card. File size can impact performance, especially when considering reddit ads cost per click optimization.

Why is my Reddit ad headline getting cut off?

Feed placements allow 150 characters, but conversation placements only allow 100 characters. If you're running multi-placement campaigns, keep headlines under 100 characters to ensure full visibility everywhere.

How do ad specs differ for SaaS campaigns?

Ad specs remain the same across industries, but reddit-ads-for-saas campaigns often benefit from 4:5 portrait video showcasing product demos with captions, as technical audiences engage more with sound-off viewing.

What creative performs best in finance advertising?

While specs are universal, reddit ads for finance typically see stronger results with educational video content (60 seconds) and data-driven image creative. Trust-building content matters more than flashy design in this vertical.

Should I access Reddit Ads through the business portal?

Yes, always use reddit for business login to access your campaign manager. This ensures you're working with the official ad platform and have access to all format options and specs.

How can I verify my ad meets all requirements?

Before launching, follow reddit advertising best practices for creative review. The platform will flag spec violations during upload, but pre-checking dimensions and file sizes saves time.

Where can I see creative best practices in action?

Explore the reddit ad library to see approved creative from other advertisers. This shows how different brands apply these specs across formats and industries.

Key Takeaways

• 4:5 portrait (1080×1350) is the optimal image/video ratio for mobile-dominant Reddit
• Keep video under 60 seconds with hook in first 3 seconds
• Headline limits differ by placement: 150 chars (feed) vs. 100 chars (conversation)
• File size limits: 3 MB images, 1 GB video (512 MB recommended)
• Always upload custom thumbnails for video ads
• Test multiple creative variants (3-5 per campaign recommended)

For comprehensive platform guidance beyond creative specs, explore how does reddit advertising work to understand the full campaign setup process. When evaluating channel mix, compare reddit ads vs facebook ads to determine optimal budget allocation across platforms.