Group images by purpose first
A batch compresses fastest and cleanest when every image shares a purpose: all blog photos, all product shots, all email attachments. Mixed batches force compromises, because a quality setting perfect for photos may wreck text-heavy screenshots.
Sort before you select. It takes a minute to separate photos from graphics, but it saves you from re-running batches with different settings — the most common batch time-waster.
One format per batch
Pick a single output format for the whole batch and stick with it. Converting everything to WebP, for example, gives you consistent results and one predictable quality curve to evaluate.
The exception: images needing transparency must stay PNG (or WebP with transparency) — JPG would flatten transparent areas to a solid color. Pull those into their own batch rather than mixing.
Find the quality sweet spot once
Because changing the quality slider re-processes the entire batch automatically, you can dial it in live: start in the middle, check the savings on the cards, zoom into a detailed image, and adjust. One good setting usually serves the whole batch.
Watch the savings percentages as you move the slider. The jump from maximum to high quality often saves 50%+ with no visible change; going lower yields diminishing returns and visible artifacts.
Review cards before downloading
Do not hit download-all blindly. Scan the cards: confirm every image processed (no errors), check that the savings look reasonable, and spot-check two or three results at full size.
Remove any image that does not belong — a misclicked file or a duplicate — before downloading. It is far easier to drop a card now than to sort it out of a ZIP later.
Handling awkward batches
Real-world batches are messy: mixed orientations, a few tiny images that barely shrink, the occasional unsupported file. Do not overthink it — each card succeeds or fails independently, and a portrait photo compresses exactly as well as a landscape one. Orientation has no effect whatsoever on compression.
Tiny images such as thumbnails or icons under 50KB may show only 0–10% savings. That is normal, not a malfunction — there is simply less redundancy to remove. If a file errors out, check its format first: the tool handles JPG, PNG, and WebP, so an HEIC, TIFF, or BMP needs converting elsewhere first. Remove it and carry on with the rest.
Finally, keep a consistent naming scheme across batches — date plus purpose — so last month's product shots never get mixed up with this month's. Organized outputs compound over time; chaotic ones quietly cost you repeat work.
Frequently asked questions
How many images can I compress in one batch?
Up to 20. They process automatically the moment you select them, each on its own card with size and savings shown.
Should I mix photos and screenshots in one batch?
Better not. Photos and graphics want different quality settings, so grouping by type gives cleaner results with less fiddling.
Can I change settings after the batch starts?
Yes — adjusting the quality slider or format automatically re-processes all images, so you can tune the whole batch live.
What if one image in the batch looks bad?
Zoom into its card at full size. If you see artifacts, raise the quality slightly — the whole batch re-processes — or handle that image in its own batch.