How to compress an image to 100 KB or 200 KB

Compress a photo in five steps

1. 1

   Open the original photo

   Go to lilcactus.app and choose File› then Open… (Ctrl+O or ⌘O), or drag the photo onto the window. Open the sample from this page to try the same settings.

   Find the original file’s size in your computer’s file information. Compare it with the exported copy.

2. 2

   Choose File › Export › JPEG…

   Choose File› then Export› then JPEG… for a photo going into a form, email or an app that asks for JPG. The dialog shows a preview on the left and export settings on the right. Give File name a name you can recognize, such as tram-small.jpg.

   Tip Does the picture need a transparent background? Choose WebP… if the destination accepts it, or PNG… JPEG fills transparent areas with white.

   

3. 3

   Lower Quality and inspect the detail

   Type 80 in Quality as a starting point. Wait for the preview and estimated size to update. Click 100% above the preview to see the saved pixels rather than a fitted thumbnail. Scroll inside the preview to inspect faces, text and sharp edges.

   If edges turn fuzzy, small text breaks up or square patches appear, raise Quality. If the picture still looks good and the file is too large, try 70. Stop at the lowest setting that preserves the detail you need.

   Tip 80% quality does not mean 80% of the original file size. The result depends on the picture and the format. Use the size at the bottom as a guide.

   

   

   

4. 4

   Reduce the output dimensions if needed

   If quality alone cannot meet the limit, tick Resize output. Type a smaller Width, such as 1200 for the sample. Its height becomes 800 automatically: the copy keeps the same proportions.

   Wait for the new estimate, then inspect the preview again. Use dimensions large enough for the destination; a form with a minimum width of 1000 pixels will not accept a 600-pixel image even if its file size is small.

   

   

5. 5

   Export and check the downloaded file

   Click Export. Open the downloaded image, check that its detail is acceptable and read its file size in your computer’s file information. If a form still refuses it, confirm the format, dimensions and size limit, then adjust your export settings.

   Aim below the stated limit: the estimate does not include image metadata, and a form may count KB differently. Export writes a new file; File› then Save writes back into the file you opened, in its own format.

   

Compress an image to 100 KB or 200 KB

There is no target-KB box. Keep the format and minimum dimensions the destination requires, then adjust Quality and Width.

• Below 200 KB: for this sample, JPEG at Quality 80 and 950 × 633 pixels downloads as 183 KB.
• Below 100 KB: for this sample, JPEG at Quality 70 and 800 × 533 pixels downloads as 95 KB.

Your photo may need different settings. If it becomes visibly damaged before reaching the limit, raise Quality and reduce Width instead. Never go below the destination’s minimum dimensions.

At the same Quality, file size roughly follows pixel count. The sample’s 1200 × 800 copy has 61% of the original pixels and 64% of its Quality-80 JPEG size. Halving both sides leaves one quarter of the pixels, so reducing dimensions often helps more than a small quality change.

Try WebP when the destination accepts it

Choose File› then Export› then WebP… and leave Lossless WebP unticked to adjust Quality. WebP keeps transparency, so it is an option for cut-outs as well as photos. Export both JPEG and WebP if you need to compare their size at an acceptable level of detail.

A Quality value of 80 is not a matching visual standard across formats. Compare the pictures, not just the numbers.

AVIF is another option, with a different quality scale

File› then Export› then AVIF… uses a different Quality scale from JPEG and WebP. For this sample, AVIF at 80 was larger than JPEG at 80; at Quality 50 it was 240 KB. On this image, 50 is a more useful starting point; small balcony and tile detail softens, so raise Quality if those details matter. Judge the visible detail rather than copying a number between formats.

AVIF shows a Document preview, which shows the open image rather than the compressed result, and has no size estimate. Reopen its exported copy to inspect it. Smaller file (slower) spends more time encoding.

What if I need compression without losing quality?

Lossless means keeping every pixel value. In PNG export, keep Preserve every color and transparency value ticked. Use a palette when possible can store an image with few colors more compactly without changing its pixels. In WebP export, tick Lossless WebP.

For a detailed photo, lossless PNG or WebP is usually much larger than a lossy JPEG, so it is unlikely to shrink an existing JPG. Lowering PNG Quality reduces colors, including transparent edges; inspect those edges before using it for a logo or signature. Resizing also removes pixels, so it is not a lossless way to shrink a file.

Image metadata › None omits camera and descriptive data; it saves a little space at most and doesn’t change pixels.

Why quality and dimensions both matter

Lossy compression, used by JPEG, stores less detail to save space. A higher Quality value keeps more detail, but even JPEG at 100% is lossy. Resizing reduces the number of pixels before compression. The exact saving depends on the photo’s detail and the encoder.

Do your edits on the original or an editable project, then export the final small copy once. Reopening a compressed JPEG and saving it repeatedly can add further damage; turning it into PNG afterward does not restore lost detail.

Fix common problems

The compressed file is bigger than the original

The original may already use a lower quality or a more compact format. Lower Quality, reduce dimensions if you can, or keep the original if it already meets the limit. Changing JPG to PNG usually does not help a photo.

The file is small enough but the form still rejects it

Check the accepted format and minimum or maximum pixel dimensions. Export a real JPEG when JPG is required; renaming a .webp file to .jpg does not convert it.

The photo looks sharp in the preview but blurry after export

For JPEG and WebP, inspect the preview at 100%, not Fit. For AVIF, inspect the downloaded file: its dialog shows the document preview.

The Quality slider will not move

Lossless WebP or Lossless AVIF is enabled. Untick it to use lossy Quality. A 16-bit PNG preserves full color precision and does not allow quality reduction.

A transparent background became white

JPEG cannot keep transparency. Export PNG or WebP instead, if your destination accepts it.

Prepare the image for its destination

• Need exact dimensions? Resize the image.
• Need a different format? Convert the image format.
• Remove unused edges before exporting: crop the image.
• Keep transparent edges: make the background transparent.

File sizes from the sample photo

The sample starts at about 782 KB. These are actual downloads from the same open original. Sizes here use 1024 bytes per KB, rounded; an upload form may count differently.

These settings are examples for this photo, not promised sizes or matching quality across formats.

Coming from another editor

Photoshop

File › Export › Export As…, then choose JPG and adjust Quality and Image Size.

GIMP

File › Export As…, use a .jpg file name, then adjust Quality in the JPEG export dialog.

Mac Preview

File › Export…, choose JPEG in Format, then adjust Quality.

Image compression: questions and answers