Resizing vs compressing an image, explained
Updated
Resizing changes pixel dimensions — a 4000px photo becomes 1200px and loses resolution. Compressing re-encodes those pixels more efficiently so a JPG, PNG or WebP file shrinks, often at the same size. You often want both. On EditItAll, Image Size resizes; the compressor re-encodes, with an optional max-dimension cap.
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Open the image compressorPixels and kilobytes are two kinds of smaller
People say they want a smaller image and mean two jobs. Resize changes the pixel grid: width × height. A 4000 × 3000 photo has 12 million pixels; at 1200 × 900 it has about 1 million. Compress changes how those pixels are stored in a JPG, PNG or WebP file. Dimensions can stay 4000 × 3000 while the file drops from several megabytes to a few hundred kilobytes.
Fewer pixels usually means a smaller file, but that is a side effect. You also lose resolution, which hurts print and later crops. Compression can leave every pixel in place. The file just uses a tighter encoding.
Resize: change width and height
Use Image Size in the EditItAll photo editor when you actually want new dimensions. Type a width or height and the editor resamples the whole picture. Shrinking a 4000px photo to 1200px is the usual web move. That cut does more for file size than compressing the 4000px original.
You give up pixels you cannot get back. The 1200px version cannot recover the discarded detail. Print, a tight crop later, or a 2× display all suffer. Enlarging is worse: the editor can only invent detail that was never captured. Cropping is a third job — it trims the frame without resampling the rest. The crop and resize guide covers that how-to.
Compress: re-encode the same pixels
Open the image compressor to shrink a file without intending a new pixel size. EditItAll re-encodes on your device. Nothing is uploaded, and it works offline after the page loads. The controls are a quality slider and an optional Max dimension cap. There is no target-KB field. File size is an output you read after each pass.
JPG, WebP and AVIF drop detail your eye often misses — that is lossy compression. A JPG compressor pass at a high quality setting can cut megabytes while the photo still looks sharp on a screen. PNG recompress is lossless: every pixel stays identical, but it only shrinks flat graphics well. Photos saved as PNG barely budge.
The Max dimension cap is a resize. If you pick 1280px, the compressor scales the long edge down, then re-encodes. That is handy when you compress a whole folder. Dedicated Image Size still belongs in the photo editor when you need an exact width and height.
Usually do both — resize first
For a website or email, pick the size you will actually display, resize to that, then compress. A 4000px JPG squeezed at medium quality is still a large file full of unused pixels. A 1200px JPG at high quality is smaller and sharper on the page that shows it.
A practical loop on EditItAll:
- Resize in the photo editor when you need exact pixels, or set the compressor's Max dimension cap for a quick downscale.
- Then compress with the quality slider. Read the in → out size on each file and nudge quality if you must go smaller.
- Keep PNG for logos, icons and screenshots. Use JPG or WebP for photographs.
Quality choices across formats are in compressing images without losing quality. More shrinking recipes live under compressing images.
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Frequently asked questions
Does resizing an image compress it?+
Not on purpose. Resizing throws away pixels, which usually cuts the file size as a side effect. Compression re-encodes the remaining pixels. A 1200px photo can still be a large JPG if quality is high, or a small one if you compress it.
Should I resize or compress first?+
Resize first to the size you will display, then compress. Dropping a 4000px image to 1200px removes most of the data. Compression then trims what is left. Doing only a quality pass on the 4000px original leaves millions of pixels you never show.
Does the EditItAll compressor change dimensions?+
Only if you set the optional Max dimension cap. That cap scales the long edge, which is a resize, then re-encodes. Leave the cap off and dimensions stay the same. There is no field for a target size in kilobytes.
Is compressing a PNG the same as resizing it?+
No. PNG recompress keeps every pixel identical and only packs the file more tightly. It helps logos and screenshots, not photographs. Resizing a PNG actually changes width and height, so you do lose resolution.
Are my files uploaded when I resize or compress?+
No. Image Size in the photo editor and the compressor both run in your browser. The file never leaves your device. After the page loads, you can go offline and it still works.