Compress an image to a target file size

Turn a KB limit into a usable image

Set a target file size to keep each result at or below an image file size limit. This tool adjusts compression toward that target size, so you do not need to guess the right quality setting. Add a static JPG, PNG, or WebP image, enter the target size in KB, and choose JPG or WebP for the result. The target size is a ceiling, not a promise that the output will contain exactly that many bytes. If the original already fits and the output format stays the same, the tool can return it unchanged with a notice.

The image file size limit is only one part of a submission requirement. A service may also specify JPG output, minimum dimensions, a particular shape, or a clear view of the subject. Use those requirements when choosing a target size. A file can fit the target size and still be unsuitable because the dimensions are too small or the selected format is not accepted.

Quality first, smaller dimensions when needed

The tool tries to reach the target file size by adjusting compression quality. If quality changes alone are insufficient, it may reduce the pixel dimensions. That second step can make a substantial difference, but it also reduces available detail. Inspect the finished dimensions along with the actual file size. Reaching the target size does not confirm that every requirement of an external form is satisfied.

Detailed scenes are harder to fit into a small target size than simple images at the same dimensions. Grass, handwriting, texture, and camera noise all affect the amount of information being compressed. Avoid expecting identical visual quality from unrelated pictures with the same target size. For documents or images with small text, readability deserves more attention than the size reduction percentage.

Check the destination before choosing a target

If the destination rejects a result very close to its ceiling, try a slightly lower target size. Services can display rounded KB values or apply their own interpretation of a size limit. A target size with a small margin is often more practical than aiming exactly at a displayed boundary. Always judge the final downloaded file, since the original and the compressed result have different sizes.

JPG or WebP for a size-limited result

Choose JPG for the target size when the receiving service accepts JPG or JPEG. It is a useful output for ordinary photos when transparency is unnecessary. Choose WebP only when the destination accepts it. A PNG input does not mean the result must remain PNG, but a form that requires PNG needs a different workflow because this target file size tool outputs JPG or WebP.

Check transparent inputs particularly carefully when choosing JPG. JPG does not retain a transparent background, so the resulting appearance needs review. When transparency is part of the required result, use an accepted format that supports it and inspect the edges. Meeting an image file size limit should not silently change the way a logo or product cutout is intended to appear.

Further reading: MDN: JPG and WebP format support

When the requested size cannot be reached

An extremely small target file size may not be achievable within the tool limits. The tool reports a failure when it cannot produce a result below the requested ceiling. Try a less restrictive target size, a simpler crop, or a source with fewer unnecessary pixels. Check whether the destination provides another accepted submission method.

If a successful result is unreadable or falls below minimum dimensions, increasing the target size may improve it, but only if the destination permits a larger file. Otherwise start with a better-framed source. Crop unused margins while retaining all required content. Do not keep compressing the same small result: return to the original so that each attempt starts with the best available detail.

Apply a target size across a batch

Batch processing applies the chosen target file size to each image individually. It does not split one shared size allowance across the group. Download finished files separately or together as a ZIP, then inspect any important result before submission. For a per-image target size, compare each result with the limit rather than comparing the ZIP total.

Processing stays in your browser and the image files are not uploaded. Check the achieved target size, then save the results before closing the page. Keep original images separately, especially if a different form later requests higher resolution. A compressed copy made for one image file size limit may be a poor starting point for another destination with different requirements.