5 MB upload ceiling: 3 specs, 1 platform
3 specs in the library limit the export to 5 MB, on 1 platform. Target sizes: 600×600, 800×800, 750×1000. File size and pixel size are different problems: a correctly sized image still gets refused if it is over the cap.
Ceiling
The export must stay under 5 MB.
Specs
3 specs on 1 platform
Compress to 5 MBAll 7 size limits
Specs capped at 5 MB
| Platform | Spec | Target size | Used for | Background | Formats | Spec page |
|---|---|---|---|---|---|---|
| Douyin Shop | Main product image (1:1) | 600×600 | Main image | Any background | JPG / JPEG / PNG | Open |
| Douyin Shop | White background image | 800×800 | Main image | Pure white (#FFFFFF) | JPG / JPEG / PNG | Open |
| Douyin Shop | Detail image | 750×1000 | Detail image | Any background | JPG / JPEG / PNG | Open |
The export must stay under this size or the upload gets rejected
How the tool gets under 5 MB
Compression runs inside your browser, so nothing is uploaded. The tool bisects the quality range: quality can move between 0.30 and 0.95, and each round encodes at the midpoint of the current range (rounded to three decimals) and measures the bytes. Over the cap, the upper bound drops to that quality; under it, the lower bound rises. That repeats for at most eight rounds and stops early once the range is narrower than 0.005.
Every passing attempt is remembered, and the export uses the highest quality that still passed — not the lowest quality it managed to reach, so detail survives wherever the cap allows it.
If all eight rounds overshoot, the tool falls back to the floor of 0.30, encodes once more and flags the result as over budget even at the floor of quality. At that point more compression will not help: shrink the target size or start from a smaller original. PNG is lossless and has no quality dial, so the tool encodes it once instead of pretending to bisect.
FAQ
Is 5 MB a pixel size?
5 MB is a file size, not a pixel size. Under one ceiling, a bigger image can afford less compression, so the tool renders at the exact pixel size the platform wants first and then spends quality to reach the cap.
What if the file is still over 5 MB after compression?
The export must stay under this size or the upload gets rejected. The tool compresses toward 5 MB; if it is still over at the 0.30 floor, the result is flagged as over budget even at the floor, and the fix is a smaller target size or a lighter original.