What reduces file size but keeps the same dimensions?
- Re-encode at a sensible quality. Cameras and editors often save JPEGs at 90 or above. Quality 75–85 looks the same at normal viewing size and is usually much smaller.
- Switch format. A photo saved as PNG is lossless and heavy; the same photo as JPEG or WebP is a fraction of the size. Going from JPEG to WebP saves another 25–35% at the same visual quality.
- Reduce PNG colors. Screenshots, logos and diagrams rarely need more than a few hundred colors. A palette of up to 256 colors (the method behind pngquant and TinyPNG) keeps them PNG, keeps transparency, and typically cuts 50–80%.
- Remove metadata. EXIF camera data, GPS location and embedded preview thumbnails add a few KB to a few tens of KB, and nobody sees them.
How much smaller will the file get?
Typical savings at the same pixel dimensions (results depend on the image)
| Starting file | Method | Typical saving | Visible change |
|---|---|---|---|
| Phone or camera JPEG | Re-encode at quality 75–80 | 40–70% | None at normal viewing size |
| JPEG | Convert to WebP at the same quality | 25–35% | None |
| Photo saved as PNG | Save as JPEG or WebP | 70–90% | None for a photo |
| Screenshot, logo or diagram PNG | 256-color palette, stays PNG | 50–80% | Usually none; smooth gradients can band |
| Any camera photo | Remove metadata | A few KB to tens of KB | None (location and camera data are gone) |
| JPEG already saved for the web | Re-encode again | 0–15% | Can add artifacts |
How do I compress an image without resizing it?
Use the Quality mode, not Target size: a target size can scale the image down when quality alone cannot reach it, while the quality slider never changes the dimensions.
- Open the compressor, or Compress JPG and Compress PNG for one format.
- Leave Limit width off. Resize is off by default on the compress pages, so the width and height stay exactly as they are.
- Set Quality: 75–80 for photos, 85–90 for screenshots with small text.
- Choose the output: Same as original to keep the format, WebP for the smallest file if the destination accepts it, or JPG for a photo that was saved as PNG.
- Compress and compare the sizes. Metadata is removed automatically.
Why did my file not get any smaller?
Two common reasons. The JPEG was already compressed at a moderate quality, as most images downloaded from websites and messaging apps are, so re-encoding gains little and only adds artifacts; when the result would be larger, the tool keeps the original instead. Or the PNG is a photo: a 256-color palette cannot hold a photo's gradients well, so save it as JPG or WebP. Why PNG files get so large explains the difference.
When is it impossible without resizing?
Every format has a floor. Below roughly 0.3 bits per pixel, JPEG turns visibly blocky and smeared. Multiply the target in KB by 8,000 and divide by the pixel count: if the result is under 0.3, the dimensions have to go down.
Largest image that can reach each target without resizing (about 0.3 bits per pixel, where JPEG starts to break down)
| Target | Largest image | Example |
|---|---|---|
| 50 KB | about 1.3 megapixels | 1,330 × 1,000 |
| 100 KB | about 2.7 megapixels | 1,900 × 1,400 |
| 200 KB | about 5.3 megapixels | 2,660 × 2,000 |
| 500 KB | about 13 megapixels | 4,160 × 3,120 |
So a 12-megapixel phone photo can reach about 500 KB at full size, already with some softening up close, but not 200 KB. For those targets, follow how to compress an image to a specific size, which resizes first.