You spent a weekend drawing, exported your set, uploaded it — and LINE rejected it. The rejection notice is famously unhelpful: it often just says the set does not meet the guidelines. Below are the actual reasons creators get turned down, in roughly the order they happen, and what to change.
1. The image is not exactly 320 × 320
This is by far the most common rejection. Not 319, not 320 × 321, not “close enough”. Every main sticker must be precisely 320 × 320 pixels. A single extra row of pixels is enough to fail validation, and it often fails silently — the upload succeeds, then the set is rejected days later.
Fix: resize to exactly 320 × 320 as the last step before export, and verify the exported file rather than trusting your editor. See the image resize guide for ways to get it exact.
2. The background is white instead of transparent
LINE composites stickers over chat bubbles using the alpha channel. If your PNG has a solid white background, the sticker shows up as an ugly white square — and reviewers reject it. Exporting as JPG guarantees this failure because JPG has no transparency at all.
Fix: export PNG with a genuinely transparent background. If your source has a white backdrop, strip it first with the background removal walkthrough.
3. main.png or tab.png is missing or mis-sized
Beyond the eight stickers, a submission needs three companion assets:
- main.png — 240 × 240. The shop thumbnail.
- tab.png — 96 × 74. The tray icon, which is wider than tall.
- A cover image — often 975 × 500. The banner shown on your set's page.
A missing asset is the most common cause of a review that stalls forever. Many creators never notice because the upload screen does not insist on them up front.
Fix: generate them from your main artwork rather than hand-cropping. The HailouTec cutter produces all three at the correct dimensions when the LINE spec option is on.
4. The artwork contains something LINE does not allow
LINE's content policy is stricter than it first appears. Commonly rejected content:
- Brand names and logos. You cannot put “NIKE” or a company name on a sticker.
- Copyrighted characters. Mario, Pokémon, Disney, anime characters — all refused.
- Celebrity likeness. Real people who did not license their image.
- Implied official affiliation. Art that suggests a partnership with LINE or a brand.
- Political or offensive content. Removed without appeal.
Short text like “thank you” or “good morning” is fine. What gets refused is text that names a brand or implies an official relationship.
Fix: read your own stickers as if you were a trademark reviewer. Replace any word that names a real company. If your sticker was adapted from fan art, do not submit it — start from your own drawing.
5. The set has too few stickers
A set needs a minimum number of stickers to be publishable. Submitting a handful of images almost always results in a rejection or a request to expand the set. The exact minimum is on the submission screen — check it before you upload.
Fix: design more poses and expressions of the same character rather than adding unrelated art. A coherent set of eight to sixteen variations works better than a padded set. See 25 sticker ideas for ways to expand a character without repeating yourself.
6. Most stickers look too similar to existing ones
LINE compares your submission against the current catalog. If your set is a set of near-duplicates of stickers that already exist — generic laughing faces, a plain thumbs-up, a standard “heart” — the set is judged low-value and rejected.
This one feels unfair because the individual stickers are technically valid, but the rejection reason is “not sufficiently original.”
Fix: give the set a recognizable style, a consistent color palette, or a specific theme that makes it unmistakably not a copy. Original characters with a consistent outline style do better than generic expressions.
7. Quality problems: blurry edges, muddy colors, off-center art
Reviewers do judge craft. The usual quality rejections are:
- Blurry or soft edges, often from scaling a small image up.
- Semi-transparent halos left behind by a rough background removal.
- Art that touches the edges and gets visually cropped in the chat panel.
- Colors that band or look washed out from heavy compression.
Fix: work at 320 × 320 from the start rather than scaling down, remove backgrounds with a clean edge, and leave a few pixels of padding around your art.
8. Technical upload problems
Sometimes the artwork is fine and the upload is the problem: an image over the file size limit, an APNG where a static PNG is expected, a filename with unusual characters, or a set where one file failed to upload and you did not notice.
Fix: confirm the file count in your submission matches the number of stickers, and re-check the review screen for any missing slot. Animated stickers have tighter limits than static ones — see the animated sticker guide.
9. You are resubmitting an unchanged set
If you fix the obvious problem and resubmit without changing anything else, you may simply get rejected again. Reviewers see a resubmission as the same submission.
Fix: change something visible — redraw at least one sticker, adjust the palette, or replace the weakest pose — so the resubmission is genuinely a different file set.
A pre-submission checklist
Before you upload, run through this:
- Every sticker image is exactly 320 × 320
- Backgrounds are truly transparent, and files are PNG
- main.png (240 × 240) and tab.png (96 × 74) are ready
- No brand names, logos, or copyrighted characters
- The set meets the minimum sticker count
- The concept is distinctive, not a set of generic expressions
- Edges are clean, no blur or leftover halos
- Art has breathing room and is not touching the edges
How long does review take?
Most sets clear within a few days, longer during busy periods. If yours has been sitting in review for more than about a week with no decision, the most likely cause is a missing main.png or tab.png rather than a content problem.
Getting it right the first time
Almost every rejection traces back to a handful of mechanical requirements: exact dimensions, real transparency, the three companion assets, and a set distinctive enough to not look like a copy. Get those four right and you remove most of the reasons a set can fail before a human reviewer ever looks at it.
If you want to check your files before submitting, the HailouTec LINE sticker cutter handles the sizing, transparency, and companion assets for you in the browser — nothing is uploaded to a server. You may also want to read the size and format guide for the full spec, or see how to split a sticker sheet if you drew several poses on one canvas.
Frequently asked questions
Why were my LINE stickers rejected?
The most common causes are an image that is not exactly 320 × 320, a background that is not fully transparent, a missing or mis-sized main.png or tab.png, artwork containing text or brand names LINE does not allow, too few stickers in the set, or stickers too similar to content already in the shop.
How long does LINE sticker review take?
Most sticker sets are reviewed within a few days, but it can take longer during busy periods. If your set sits in review for more than about a week, check that main.png and tab.png were uploaded correctly, because missing assets are the most common cause of a stalled review.
Can I sell stickers that contain text or company names?
Simple text such as short captions and greetings is generally fine. Brand names, logos, copyrighted characters, celebrity likeness, and anything implying an official partnership are not allowed and are a frequent reason for rejection.
Does every sticker in a set need to be 320 × 320?
Yes. Every main sticker image in a standard set must be 320 × 320 pixels with a transparent background. Popup stickers are the exception and can be larger, up to 480 × 480.
Why was my sticker set flagged as too similar to an existing one?
LINE compares submissions against the existing catalog. If most of your stickers closely resemble stickers that are already published, the set is judged low-value and rejected. Make the set visually distinct or change the concept.