How to compress many photos at once without uploading them

Thirty holiday photos, a form that caps the total at 10 MB, or a shared album that chokes on 8 MB phone pictures. Doing them one at a time is tedious, and most bulk tools want every picture on their server first.

Step by step

1. Open the image compressor and choose choose files. In the file dialog, select several photos: Ctrl+A for a whole folder, Ctrl-click (⌘-click on a Mac) for some of them, or drag a selection from your file manager onto the drop area. On a phone, most galleries let you tick several pictures.
2. Set Max width (1920 is a safe all-rounder, 1280 for email) and leave Quality at 80. Optionally type a target file size such as 500 KB; it applies to each photo, not the total.
3. Watch the table fill in: before and after size for every file, plus a GPS removed badge where the original had location data. Change any setting and the whole batch is redone with the new values.
4. Press Download all (ZIP) for one file named compressed-images.zip, or Save on single rows. Files that share a name (two IMG_0001.jpg from different cameras) get -2, -3 so nothing is overwritten inside the ZIP.

The limit is 50 photos (and about 300 MB of originals) per batch, which keeps a phone browser from running out of memory. Run a second batch for more.

How big will the batch be?

A rough rule for everyday photos saved as JPEG at quality 80:

Busy scenes (leaves, gravel, confetti) sit at the top of each range; skies and walls at the bottom. To fit a total limit, divide it by the number of photos and use that as the per-photo target: 25 MB for 40 photos is about 600 KB each.

Which settings to use

• Photos for email, chat or a web form: JPEG, quality 75 to 80, max width 1600 to 1920.
• Photos for a website gallery: WebP often comes out 25 to 35% smaller than JPEG at the same look, and every current browser shows it.
• Screenshots: PNG keeps text sharp; resizing helps more than anything else. If a screenshot is mostly a photo, JPEG wins.
• A mix of PNGs with transparency and photos: “Same as original” keeps PNGs as PNG and JPEGs as JPEG, so logos keep their clear background.

Why “no upload” matters more for a batch

A single photo might be harmless. A folder of thirty usually is not: faces of other people, your house number, car plates, documents on a desk, and the GPS tag on every picture that together map out where you live and travel. Uploading a batch hands a stranger all of it at once. Browser-side compression reads each file, draws it onto a canvas and saves a brand-new image, so there is no copy anywhere else and the location tags are not carried over.

A quick way to check any tool: load the page, switch your device to airplane mode, then compress. If it still works, the pictures never left.

Doing it from a terminal instead

For hundreds of files, or as part of a script, these do the same job locally:

# ImageMagick: resize to at most 1920 px wide, quality 80, strip metadata, write into ./small
mkdir -p small && magick mogrify -path small -resize '1920x>' -quality 80 -strip *.jpg

# libvips (faster, lower memory)
for f in *.jpg; do vips thumbnail "$f" "small/%s.jpg[Q=80,strip]" 1920; done

# macOS built-in
mkdir -p small && sips -Z 1920 *.jpg --out small

-strip (or strip in vips) is what removes EXIF and GPS; without it the location tag survives resizing.

Related

Remove location from many photos without re-compressing · How low can JPEG quality go? · Rotate many photos at once · Batch rename the files afterwards (names only, preview first) · Why a ZIP of photos can be larger than the photos · Interactive packing lesson · Why zipping photos does not make them smaller · Compress an image without uploading it · Resize an image without uploading it · Photo too large to email · Remove GPS from a photo · Image compressor (single or batch)

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Published 8 November 2026 · updated 9 November 2026.