After resizing, do I still need to run the image through the compressor?
Often not. The resizer itself saves JPEG or WebP at the quality you choose, 90 by default, and shows the resulting size before you download. If the size is still more than you need, lower the quality in the resizer itself. The compressor is for batches of photos, or for files whose dimensions are already right.
Two different jobs, with some overlap
- Resizing cuts the number of pixels: a 4032 × 3024 photo becomes, say, 1600 × 1200 with the ratio lock on. That alone makes the file much lighter.
- Compressing cuts the weight of each pixel: the dimensions stay the same, and saving gives up fine detail according to the quality.
- The overlap: the resizer also saves at a quality you pick, so it shrinks and compresses in one step.
Why one step beats two
Every time you save as JPEG or WebP, some detail is given up. Resize and save at 90, then open the result in the compressor and save at 80, and the picture has gone through two saves in a row, with the losses stacking. Resize and save at 80 directly, and it has gone through one save only: a similar size and a cleaner result.
A 4032 × 3024 photo: type a width of 1600 with the ratio lock on and the height becomes 1200.
Pick JPEG, leave quality at 90, and note the new size in the results table.
Move the quality to 80 and the size in the table updates. Compare the two figures and the preview, and keep what is enough.
When the compressor really helps
- When the photos already have suitable dimensions and only need to be lighter.
- When you have a set of photos: the Image compressor takes up to 30 at a time, while the resizer handles one image at a time.
- When you want the before and after size of every photo in a set at once.
If you do need both, keep the order clean: resize first as PNG to avoid loss, then compress once. Or resize as JPEG at a very high quality, then compress. The point is not to save at a middling quality twice.
The practical summary
One photo: open the Image resizer, type the dimensions, pick JPEG or WebP, lower the quality until the size suits you, and download. Done. Twenty photos already at the right dimensions: the compressor. Twenty oversized photos: resize each one as PNG or at high quality, then compress them all together.
Common questions
Why is the quality slider sometimes missing in the resizer?
Because the output format is PNG, either chosen by you or as the 'Original format' of a PNG file. PNG gives up no detail, so it has no quality setting.
Does quality 90 mean the same in both tools?
Both use the browser's own encoder for the same format, but the resulting size depends on the picture and its dimensions, so always watch the figure shown.