What size should a Threads ad image be?

Use 1080 × 1350 px at a 4:5 ratio for single-image ads to fill the most feed space. Square 1:1 also runs, and story-format ads should be 1080 × 1920 px at 9:16.

How long can a Threads video ad be?

A single video ad can run up to about 2 minutes, a story ad up to 60 seconds, and a boosted organic post up to 5 minutes. Keeping the hook in the first three seconds matters more than the maximum length.

What is the character limit for Threads ad copy?

Primary text is capped at 500 characters, matching the organic post limit, and the headline field allows up to 40 characters. Story and full-screen placements have no separate caption field, so text must be in the creative.

How many cards can a Threads carousel ad have?

A carousel ad supports between 2 and 10 cards. Use a consistent aspect ratio across every card — typically 1:1 — so the swipe feels seamless and nothing gets cropped unevenly.

What file formats and sizes do Threads ads accept?

Images are accepted as JPG or PNG and video as MP4 or MOV. Image and most creatives cap around 30 MB, while video ads allow larger files up to roughly 250 MB depending on placement.

Threads Ad Spec Reference

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Build Threads ads to spec the first time

Threads ad placements each carry their own dimensions, file caps, and copy limits, and getting one wrong means a rejected or cropped ad. This reference pulls every placement into a single tool: pick a format and it returns the exact size, aspect ratio, accepted file types, video length ceiling, and the primary-text and headline character limits, with a built-in tester for your copy.

How it works

Select an ad placement and the tool surfaces its full specification. Where the placement has a caption field, paste your primary text and the tool counts visible characters — emoji included as one each — against the 500-character limit, flagging any overage in red so you trim before submitting to review.

Placement reference

Single image ad: 1080 × 1350 px, 4:5, up to 30 MB
Single video ad: 1080 × 1350 px, 4:5, up to ~2 min and ~250 MB
Carousel ad: 1080 × 1080 px, 1:1, 2–10 cards
Story / vertical ad: 1080 × 1920 px, 9:16, creative-only text
Boosted sponsored post: 1080 × 1350 px, 4:5, uses your original caption

Across placements, primary text is capped at 500 characters and the headline at 40 characters.

Tips

Design vertical wherever the placement allows — 4:5 and 9:16 dominate the feed and full screen respectively. For video, front-load the message into the first three seconds and add captions, since many viewers watch muted. On story and full-screen ads there is no caption field, so any text must be baked into the creative and kept inside the safe zone, away from the interface chrome at the top and bottom.