Join your artwork in order or split it with source-scoped platform targets, then save a checked ZIP. Files stay on this device.
Use this toolkit when you own a long comic page or ordered panels and need upload-sized image files. It cuts at exact source rows, numbers each piece, reopens the encoded files and includes their dimensions and bytes in a ZIP report. Naver Challenge Comics has a documented 690 px width and JPG/GIF format; this tool exports JPG for that profile. WEBTOON has an 800×1280 splitting notice. Its 2 MB per image and 20 MB episode figures are conservative export targets from regional guidance and a 2025 contest FAQ, not a permanent universal upload promise. Postype allows PNG/JPG up to 10,000 px per side and 50 MB per image. Inspect every proposed cut around dialogue before posting.
Drop image files hereProcess many files at onceNo upload · processed on this device
Making a game?
Nerulio is a 2D game asset studio first: draw pixel art, cut sprite sheets into animations, pack texture atlases, check autotile tilesets and export them for Godot, Unity, Phaser and other engines. It runs in your browser; files stay on your device.
A vertical episode has reading rhythm: a blank gutter may mark a scene break, while white inside a panel or speech balloon can look just as empty to software. The default cut height produces predictable files. You can edit the source row of each cut and undo changes. The red preview lines are locations, not a claim that the narrative remains intact.
The worker checks image dimensions before full decoding and refuses an input above 64 megapixels, 32,767 px on a side or 80 MB. It processes one source and output tile at a time and decodes each encoded output again. JPG flattens transparency onto the chosen matte. A ZIP report records source rows so you can check coverage.
Source row
A horizontal coordinate in the original image. Cuts at rows 1280 and 2560 create ranges 0–1279, 1280–2559 and 2560 onward.
Upload target
A conservative pixel or byte budget for export. The publisher may change its uploader or use a different regional workflow.
PPI / LPI
Output pixels per inch divided by screentone lines per inch gives the dot-cell pitch in pixels. A 300 PPI output at 60 LPI has a 5 px pitch.
Worked example: one 800×3000 page
A CC0 test page 800 px wide and 3000 px tall uses two cuts at source rows 1280 and 2560.
Check a 100% seam view at both cuts. For a comic with speech or faces at either line, change the row even if the dimensions already satisfy an export profile.
Check the result
Open the ZIP in another program, count the numbered files and reopen each image. Compare the dimensions and actual bytes with export-report.json.
Check that sourceY and sourceHeight cover every input row in order. For JPEG, inspect the visible seam and any flattened transparency rather than claiming pixel-for-pixel preservation.
Preview the complete episode in reading order and inspect speech, faces and gutters at actual size before using a publisher dashboard.
Troubleshooting
Symptom
Likely cause
How to check
Fix
A dialogue bubble is cut
An even-height target crosses the panel
Zoom to each red cut line
Change the source row and export again
The JPG has a white area where transparency was
JPG has no alpha channel
Compare the input and the chosen matte colour
Choose PNG where that profile permits it, or set an intended JPG matte
The page is refused before import
Dimensions or file bytes exceed the worker memory budget
Read the exact size in the error
Split the page in a drawing app before loading it here
A file misses the byte target
Detailed art stays large after JPEG quality reduction
Read the per-file message and ZIP report
Shorten the slice or use a smaller custom width, then visually inspect the result
Other ways to do it
Option
When it is the better choice
The publisher’s current upload dashboard
Use it to verify current rules and acceptance; this toolkit cannot approve an episode on behalf of a platform.
A layered drawing app
Use it when you need to rearrange panels, redraw speech or preserve editable layers. The toolkit operates on flattened still images.
What this page does not cover
The cut line cannot identify every face, speech balloon or story beat; manual review is necessary.
No Kakao or Lezhin upload dimensions are claimed. Their public submission pages did not establish a self-publishing raster rule.
A 64 MP input limit and browser codecs can reject very long pages; this does not mean the publisher disallows them.
Speed lines, balloons and screentones are original SVG/PNG overlays; printing and platform acceptance require independent review.
Versions and sources
Publisher pages checked 2026-09-29. Naver Help refers specifically to Challenge Comics: 690 px exact width, JPG/GIF, 5 MB each and 50 MB total; it does not state a maximum height. The general WEBTOON notice describes 800×1280 slicing. The French Creator Academy lists 2 MB per image and 20 MB per episode; a 2025 competition FAQ has a narrower contest scope, so those bytes are treated as conservative targets. Postype Help states PNG/JPG, at most 10,000 px per side and 50 MB per image; its 700 px figure is display width. Platform upload acceptance and search demand are unverified.
Join your artwork in order or split it with source-scoped platform targets, then save a checked ZIP. Files stay on this device.
How it works
Add images
Adjust settings and review the result
Download a new file
Supported formats
PNG / JPG / WebP → reopened JPG / PNG pieces + JSON report (ZIP). Local browser decoding and encoding; animated inputs are not supported.
What this tool does
Join your artwork in order or split it with source-scoped platform targets, then save a checked ZIP. Files stay on this device.
Implementation and verified quality
basic · local image worker / source-row partition / re-decoded PNG or JPEG / stored ZIP. Quality qualification is in progress. Pro/Flagship quality has not been established.
Before you export
Cut lines cannot judge dialogue or panel safety. Platform acceptance is unverified; WEBTOON byte budgets are conservative export targets.
Frequently asked questions
What are this tool’s limitations?
Cut lines cannot judge dialogue or panel safety. Platform acceptance is unverified; WEBTOON byte budgets are conservative export targets.
Are my files uploaded?
This tool processes the files you open on your device without uploading them. Images you explicitly attach to community posts are uploaded separately. Optional engines and models are downloaded from third parties; those requests expose connection information such as your IP address.
Will my work be saved automatically?
No. Images and editing state stay in this tab; media output can use local temporary storage. Changing language preserves your work; reloading, closing the tab, or following a link to another page can clear it.