Reddit ad specs can humble even seasoned paid social managers. The units look like normal posts, but the requirements behind image, video, carousel, and conversation placements are all slightly different: dimensions, file limits, character caps, the works. Miss one detail and you are looking at a rejection, or a creative that technically runs but looks rough on mobile (where most Redditors live).
Everything below is meant to be a single, no-drama reference for Reddit ad sizes, file types, aspect ratios, headlines, CTAs, and creative rules. If you are ramping spend for the first time or tightening creative QA for an agency client, these tables and notes reduce rejected uploads and the back-and-forth of review cycles. And if you are trying to keep specs aligned across channels, you can compare against our Meta ad specs, Google Ads specs, TikTok ad specs, and LinkedIn ad specs guides.
Reddit Ad Formats: A Quick Orientation
Reddit has a handful of ad formats that each blend into a different part of the product. Pick the format based on what you are trying to accomplish first; pixel math comes second. Here is the set of Reddit ad formats available to advertisers in 2026:
- Image Ads (promoted posts with a single static image or GIF)
- Video Ads (autoplay video within the feed)
- Carousel Ads (swipeable multi-card units with 2 to 6 images or GIFs)
- Conversation Ads (placements that appear inside comment threads)
- Free-Form Ads (rich-text promoted posts combining text, images, video, and links in a single unit)
Product ads (dynamic, catalog-driven units) are still in limited beta as of mid-2026, so most teams will not have access. If you are in ecommerce and have catalog eligibility, your Reddit account rep is the fastest path to confirmation. For everyone else, the five formats above cover the Reddit promoted post specs you will actually use.
Each Reddit ad format maps to a distinct placement — most land in the feed, while Conversation Ads appear inside comment threads.
Reddit Image Ad Specs
Image ads are the default unit for a lot of Reddit budgets because they are fast to produce, fast to test, and easy to iterate. They run as promoted posts across the home feed, popular feed, and subreddit feeds. The specs themselves are clean, but Reddit supports three aspect ratios, and the right choice depends on how mobile-heavy your targeting is and how much you care about desktop presentation.
| Spec | Requirement |
|---|---|
| File types | JPG, PNG, GIF (GIFs may display as static images) |
| Recommended resolutions | 1080x1080 (1:1), 1080x1350 (4:5), 1920x1080 (16:9) |
| Aspect ratios | 1:1, 4:5, 16:9 |
| Max file size | 3 MB |
| Headline | Up to 300 characters |
| Body text (optional) | Up to 300 characters (shown below headline on some placements) |
| CTA button | Required; select from preset list (Learn More, Shop Now, Sign Up, etc.) |
| Destination URL | Required; must be a valid landing page |
| Source: Reddit Ad Unit Specifications (business.reddithelp.com), 2026. |
One practical callout on Reddit ad dimensions for images: 4:5 buys you the most vertical real estate on mobile, which is why it tends to pull higher engagement in feed placements. Square (1:1) is the safest choice when you need one asset to behave predictably across placements. Landscape (16:9) can look great in desktop-leaning subreddits, but it gets squeezed on phones. Reddit creative best practices found that images with a visible logo drove 108% higher average conversion rates than creatives without one, so do not hide the brand mark in the fine print.
Reddit Video Ad Specs
Video is usually where Reddit campaigns pick up their biggest engagement lift, especially in interest-based subreddits where people are already in a content-consuming mindset. Reddit video ad specs give you plenty of room on file size, but they are picky about format and execution details.
Key video requirements:
- File types: MP4 or MOV only
- Max file size: 1 GB
- Recommended length: 5 to 30 seconds (max 15 minutes, but completion rates drop sharply past 30s)
- Aspect ratios: 1:1, 4:5, 16:9
- Recommended resolution: At least 720p; 1080p preferred
- Sound: Optional but recommended (captions strongly advised since many users browse muted)
- Thumbnail: Auto-generated or custom upload; 1200x628px recommended
Note: Tip: Reddit videos autoplay on mute in the feed. If the first three seconds depend on voiceover, you are betting against the scroll. Lead with motion and on-screen text so the hook survives without sound.
Text rules for video ads follow the same structure as image: up to 300 characters for the headline, a required CTA button, and a destination URL. If you are repurposing assets from Meta, our Meta video ad specs workflow guide breaks down the differences around encoding, aspect ratio priorities, and safe zones so your edits are intentional instead of trial-and-error.
Match your Reddit video ad aspect ratio to your target device for maximum feed visibility.
Reddit Carousel Ad Specs
Carousel ads are built for sequencing: a mini story, a feature walkthrough, or a tight product lineup without forcing the user to bounce between posts. Reddit carousel ad specs support 2 to 6 cards. Each card can be a static image or GIF, but you cannot drop video into the carousel itself (video needs its own standalone unit).
| Spec | Requirement |
|---|---|
| Number of cards | 2 to 6 |
| Card file types | JPG, PNG, GIF |
| Recommended card size | 1200x1200 px (1:1) |
| Max file size per card | 20 MB |
| Headline (per card) | Up to 300 characters |
| CTA button | One CTA per carousel (not per card) |
| Destination URL | One URL per carousel or unique URLs per card |
| Reddit carousel specs as documented in Reddit's official ad unit specifications. |
Reddit's 20 MB per-card limit is generous versus most paid social platforms, which means you can keep product photography crisp or run a detailed GIF without turning it into mush. The tradeoff is performance: six heavy GIFs can feel slow on anything less than a great connection. When you can, treat 5 MB per card as a working target and only go heavier when the extra detail is doing real conversion work.
Conversation Ads and Free-Form Ads
Conversation ads are Reddit's signature placement, and they behave differently because they do not live in the main feed. They show up inside comment threads, putting your message in the middle of an active discussion. Reddit reports that 43% of redditors spend time in conversation threads, and campaigns running feed and conversation ads together saw 83% higher brand awareness than feed alone.
Conversation placements can run standard ad types (image, video, carousel). The specs difference is mostly about how the placement reads: your ad sits next to user comments, so anything that feels like a polished brand announcement tends to get ignored (or worse, dragged). For this placement, keep headlines under 100 characters so they scan cleanly on mobile, and remember Reddit uses a 400x300px thumbnail in the collapsed preview state.
Conversation ads appear mid-thread, blending with organic comments for higher engagement.
Free-Form Ads give you the most room to sound like you belong on Reddit. They combine text, images, video, and links into a single promoted post that looks like a detailed organic submission. They are effectively Reddit's version of a long-form social post. Body text does not have a strict character limit (even though shorter usually wins), and you can include multiple media elements. Free-form ads are a strong fit for product launches, AMAs, and educational content where the goal is to earn attention the way a real post would.
Reddit Ad Character Limits and Creative Specs at a Glance
A lot of Reddit rejections are not strategic mistakes; they are simple spec misses: too many characters, the wrong file type, an oversized image. The table below pulls the core Reddit ad creative specs into one checklist so your team can QA once and move on.
| Element | Image Ad | Video Ad | Carousel Ad | Conversation Placement |
|---|---|---|---|---|
| Headline max | 300 chars | 300 chars | 300 chars per card | 100 chars recommended |
| Body text max | 300 chars | 300 chars | N/A | 300 chars |
| CTA button | Required (preset) | Required (preset) | Required (one per unit) | Required |
| Image file types | JPG, PNG, GIF | N/A | JPG, PNG, GIF | Varies by ad type |
| Video file types | N/A | MP4, MOV | N/A | MP4, MOV |
| Max file size | 3 MB | 1 GB | 20 MB per card | Per ad type |
| Thumbnail | N/A | 1200x628 recommended | N/A | 400x300 |
| All specs sourced from Reddit's official ad unit documentation, 2026. |
Reddit Ads Best Practices for Community-Native Creative
Specs get you through review. Creative gets you paid attention. Reddit users tend to respond better to ads that feel community-native rather than overly polished, and tactics that print on Meta or TikTok often underperform here. The patterns below are the difference between campaigns that earn clicks and campaigns that get scrolled past (or downvoted into oblivion).
Write like a Redditor, not a brand. The best-performing headlines read like post titles, not taglines. Skip lines like "Discover Our Revolutionary New App" and write something that could plausibly live in the subreddit: "I built a tool that does X, and here is what I learned." Reddit rewards plainspoken specificity and punishes corporate-speak with downvotes, which can hurt relevance and push CPMs up.
Include your logo, but keep it subtle. Reddit's 2026 internal data showed a 108% conversion rate lift when a logo is visible. That is not permission to plaster a watermark across the creative. Use a corner placement or a natural integration in the product shot so the brand is clear without hijacking the post aesthetic.
More creative rules that matter:
- Use 4:5 aspect ratio for mobile-first campaigns; it dominates the viewport on scroll
- Keep video under 15 seconds for awareness objectives, 15 to 30 seconds for consideration
- Add captions to every video (Reddit defaults to muted autoplay)
- Test carousel ads for product catalogs; the swipe mechanic drives curiosity clicks
- Avoid stock photography that looks generic; Redditors will call it out in comments
- Match your landing page tone to your ad copy; a jarring shift from casual ad to corporate LP kills conversions
Five community-native creative practices that consistently lift Reddit ad performance.
Note: Info: On Reddit, the comments are not an afterthought; they are part of the placement. People can (and will) reply to promoted posts. Watch the thread and respond like a human. A well-managed comment section can extend reach well beyond the paid delivery.
Connecting Paid Reddit Campaigns to Organic Visibility
Most paid social teams run Reddit like a silo: launch the campaign, watch the CTR, move on. That leaves value on the table. Reddit threads show up in Google results more and more, and they are also pulled into AI answer engine responses. If a promoted post sparks real discussion, it can keep earning impressions long after the budget line hits zero.
Reddit is no longer just a paid media placement or community research channel. It is increasingly part of how buyers discover brand conversations through Google and AI answer engines. For the organic side of this shift, see our breakdown of Reddit's May 2026 visibility surge and what it means for SEO teams after Google's core update.
That is why it matters to monitor brand presence across both traditional search and AI answer platforms. Vizup helps teams track how their brand shows up in Google results and AI-generated answers, so you can spot the moment a Reddit thread (paid or organic) starts carrying search visibility. When a conversation ad kicks off a thread that ranks for a branded query, you want that signal quickly so you can build around it.
If you are pairing paid Reddit with programmatic SEO, the loop gets tighter: paid spend drives community engagement, engagement creates indexable discussion, and that discussion feeds organic visibility across Google and AI search surfaces. Vizup's monitoring tools help you measure each stage so you are not guessing where the lift is coming from.
Vizup monitors each stage of the paid-to-organic loop, from Reddit ads to AI answer engine visibility.
Common Mistakes That Get Reddit Ads Rejected
Reddit review is stricter than a lot of marketers expect, especially around misleading claims and community standards. These are the rejection triggers that tend to blindside teams:
Wrong file format for video. Reddit only takes MP4 and MOV. Upload a WebM or AVI and you will get rejected immediately. It is a basic miss, but it happens constantly when teams pull exports built for YouTube or programmatic display and assume they will pass everywhere.
Exceeding the 3 MB image limit. High-res PNGs (especially with transparency) blow past 3 MB fast. Convert to JPG or compress before upload. Carousel cards get 20 MB each, but do not let that lull you into thinking standard image ads have the same wiggle room.
Clickbait headlines. Reddit flags exaggerated claims and engagement-bait phrasing ("You won't believe..."). Write a straightforward, informative headline that would not look out of place as a real post title in the subreddit you are targeting.
Broken destination URLs. Every ad needs a valid landing page that loads cleanly. Long redirect chains through tracking domains can trigger review issues. Before you submit, open the destination URL in an incognito browser and make sure it resolves exactly the way a user will see it.
Key Takeaways
- Reddit ad specs vary meaningfully across image, video, carousel, and conversation placements. Do not assume one set of dimensions covers all formats.
- 4:5 is the highest-impact aspect ratio for mobile feed placements. Use 1:1 as a safe default when you need cross-placement flexibility.
- Video ads support up to 1 GB files but should stay under 30 seconds. Always add captions.
- Feed and Conversation Ads together can improve brand awareness versus feed-only campaigns and deserve dedicated creative testing.
- Write ad copy that reads like an organic Reddit post. Community-native tone is not optional on this platform.
- Monitor how Reddit threads (paid and organic) surface in Google and AI answer engines using tools like Vizup to close the loop between paid spend and long-term organic visibility.
Frequently Asked Questions
What are the recommended Reddit ad dimensions for image ads?
Reddit supports four image ad aspect ratios: 1:1, 4:5, 4:3, and 16:9. If you are optimizing for mobile, 4:5 takes up the most screen space and typically drives stronger engagement in-feed.
What is the maximum Reddit ad file size for video?
Reddit video ads can be up to 1 GB, and the platform accepts MP4 or MOV. Even with that ceiling, smaller, well-encoded files (under 100 MB when possible) load faster and feel better for mobile users.
How many cards can a Reddit carousel ad contain?
Reddit carousel ads support 2 to 6 cards. Each card can be a JPG, PNG, or GIF up to 20 MB, with 1200x1200 pixels (1:1) as the recommended size.
Do Reddit conversation ads use different specs than feed ads?
Conversation ads can run the same creative types as feed ads (image, video, carousel), but the placement changes how the unit is consumed. Keep headlines under 100 characters for mobile readability, and plan for a 400x300px thumbnail in the collapsed preview. More than anywhere else on Reddit, the creative needs to read like it belongs in a live thread, not a polished announcement.
How can I track whether my Reddit ads are generating organic search visibility?
Reddit threads often surface in Google results and AI-generated answers, so paid activity can create organic lift when it sparks real discussion. Tools like Vizup help teams monitor brand mentions and visibility across search engines and AI answer engines, making it easier to spot when a promoted thread starts ranking and adjust accordingly.
