---
title: "Compress image to 3 MB — free, saved as JPG | Herofab"
description: "Compress photos under 3 MB in your browser. Saved as JPG and never cropped: quality first, pixel size only when needed. Free; nothing is uploaded."
url: https://herofab.app/tools/compress-image-to-3mb
language: en
updated: 2026-10-19
---

# Compress an image to 3 MB.

Drop your photos and download each one as a JPG under 3 MB. The quality is lowered first and the pixel dimensions only when that is not enough; the photo is never cropped. It runs in your browser; nothing is uploaded.

![Black-dial watch with a mesh strap on white, three-quarter view · Compress image to 3 MB](https://herofab.app/img/ex/watch-packshot-1100.webp)

Made with Herofab · Packshot studio

## Under 3 MB per image, saved as JPG

Limits come from each platform's own help pages, summarised in the [guides](https://herofab.app/guides/) (checked 24 September 2026).

## Who asks for 3 MB.

Lines from Herofab's platform guides that name 3 MB, as a limit, a recommendation or one end of a range. Each row links to the guide and its official source.

| Platform | Rule | What the guide says | Read |
| --- | --- | --- | --- |
| [Miinto](https://herofab.app/guides/miinto-image-requirements) | File size | Maximum 3 MB | 11 October 2026 |
| [Coupang](https://herofab.app/guides/coupang-product-image-requirements) | File size | 10 MB or less in the seller academy's listing guide; 3 MB or less through the product API | 11 October 2026 |
| [Temu](https://herofab.app/guides/temu-product-image-requirements) | File size | 3 MB or less per image | 12 October 2026 |
| [Temu](https://herofab.app/guides/temu-product-image-requirements) | Size chart image | JPEG, JPG or PNG, at least 800 pixels wide and 800 pixels high, aspect ratio (width to height) of at least 1:3, 3 MB or less | 12 October 2026 |
| [Reddit Ads](https://herofab.app/guides/reddit-ad-image-size) | File size | Maximum 3 MB for an image ad; in a carousel 20 MB per file and 3 MB for GIFs; maximum 10 MB for free-form ad images | 12 October 2026 |
| [Reddit Ads](https://herofab.app/guides/reddit-ad-image-size) | Thumbnail | Recommended landscape 4:3 at 400 × 300 pixels; square 1:1 at 300 × 300 and landscape 16:9 at 400 × 225 pixels are acceptable; maximum file size 3 MB; shown only in conversation placement and compact view | 12 October 2026 |
| [SHEIN](https://herofab.app/guides/shein-product-image-size) | File size | 3 MB or less per image | 12 October 2026 |

[Miinto image compressor](https://herofab.app/tools/miinto-image-compressor) · [Temu image compressor](https://herofab.app/tools/temu-image-compressor) · [Reddit Ads image compressor](https://herofab.app/tools/reddit-ads-image-compressor) · [SHEIN image compressor](https://herofab.app/tools/shein-image-compressor)

## 3 MB in numbers.

Counted as the compressor counts: 1 KB is 1,000 bytes and 1 MB is 1,000,000 bytes. Bits per pixel divides the limit in bits by the pixels of a 12-megapixel phone photo (4,032 × 3,024 px) kept at full size; the uncompressed size counts 3 bytes per pixel.

- **Bytes:** 3,000,000
- **Bits:** 24,000,000
- **Pixels in a 12-megapixel phone photo:** 4,032 × 3,024 = 12,192,768
- **Bits per pixel at full size:** 24,000,000 ÷ 12,192,768 = 1.97
- **Uncompressed, 3 bytes per pixel:** 36,578,304 bytes, 12.2 times the limit

## Other limits.

[100 KB](https://herofab.app/tools/compress-image-to-100kb) · [500 KB](https://herofab.app/tools/compress-image-to-500kb) · [1 MB](https://herofab.app/tools/compress-image-to-1mb) · [2 MB](https://herofab.app/tools/compress-image-to-2mb) · [4 MB](https://herofab.app/tools/compress-image-to-4mb) · [5 MB](https://herofab.app/tools/compress-image-to-5mb) · [6 MB](https://herofab.app/tools/compress-image-to-6mb) · [8 MB](https://herofab.app/tools/compress-image-to-8mb) · [10 MB](https://herofab.app/tools/compress-image-to-10mb) · [Image compressor](https://herofab.app/tools/image-compressor)

## 3 MB, answered.

**Which platforms ask for 3 MB?**

Miinto, Coupang, Temu, Reddit Ads, and SHEIN. The table on this page gives each rule in full and links to the platform's guide.

**How many bytes is 3 MB?**

3,000,000 bytes: the compressor counts 1 MB as 1,000,000 bytes, the stricter of the two common readings. Counted in units of 1,024, 3 MB would be 3,145,728 bytes, so a file under 3,000,000 bytes is under the limit on either count.

**How many bits per pixel does 3 MB leave for a 12-megapixel photo?**

1.97, if the photo keeps all 12,192,768 pixels (4,032 × 3,024): 24,000,000 bits divided by 12,192,768. Uncompressed, at 3 bytes per pixel, the photo is 36,578,304 bytes, 12.2 times the limit. The compressor lowers the JPG quality first and reduces the pixel dimensions only when that is not enough.