Free Bulk Image Resizer

How bulk image resizing works here

Bulk image resizing means applying one set of rules to many photos in a single pass, instead of opening each file, typing the same numbers and saving it again. Add up to 10 images (each up to 50 MB), choose the rule, and every image in the queue is processed with it. The results can be downloaded one by one or as a single ZIP archive.

Nothing leaves your device. The photos are decoded, scaled and re-encoded in your browser, and the ZIP file is assembled there too, so there is no upload queue, no account and no waiting on a server. The flip side is that the work uses your own device's memory, which is the reason for the 10-image cap: a batch of ten 24-megapixel photos is a lot of raw pixel data to hold at once, especially on a phone. For larger sets, run several batches of ten; the settings are quick to repeat.

Percentage or fixed pixels?

Bulk mode offers two ways to size a batch, and the right one depends on how uniform your photos are.

• Percentage scales every image relative to its own size. At 50%, a 4000 × 3000 landscape becomes 2000 × 1500 and a 3000 × 4000 portrait becomes 1500 × 2000. Each keeps its shape, so this is the safe choice for mixed folders of portrait and landscape shots.
• Fixed pixels sets the same width and height for the whole batch. It suits sets that already share a shape, such as product photos shot on one tripod, where you need every file to come out at exactly 1000 × 1000 or 1200 × 800.

You can also set a target file size, for example under 200 KB per image, and each photo is optimized on its own to fit. Because every image is different, a busy photo and a plain one will land at different quality levels even though both stay under the limit.

Fix individual photos without leaving the batch

Real folders are never perfectly consistent. Every image in the queue has its own Crop, Rotate and Preview controls, and you can delete any photo that should not be in the batch. That means you can straighten the one sideways picture or trim the one with a stray object in the corner, then run the whole set with a single click. Presets can be applied to a batch as well, which helps when a platform has a published size requirement.

Practical batch workflows

• Online shop listings. Marketplaces want consistent square or near-square images. Crop outliers, then resize the batch to the same pixel size, such as 1000 × 1000, using the e-commerce preset as a starting point.
• Email attachments. Most mail services cap a message at around 20-25 MB. Ten unedited 5 MB photos exceed that. At 50% scale, the same ten files are usually a small fraction of the size and send comfortably.
• Blog and event galleries. Camera originals of 4000+ pixels slow a page down. Resizing to 1600 px on the long edge, or using the blog preset, cuts load time with no visible change on a normal display.
• Form and portal uploads. Several documents with the same limit, such as scans that must each be under 200 KB, can be done together with a 200 KB target.
• iPhone photos for other systems. HEIC files are decoded in the browser, so a batch of them can be converted to JPG for software that does not read HEIC.

Converting formats in a batch

Besides sizing, you can choose the output format for the whole batch: JPG, PNG, WebP or AVIF. Moving a set of JPGs to WebP typically makes them noticeably smaller at similar quality, which is useful for websites. Two cautions apply. First, every lossy re-encode discards a little data, so convert from your originals rather than from files that have already been compressed several times. Second, AVIF takes longer to encode than JPG or WebP, so a batch of large photos finishes more slowly. Converting PNGs with transparency to JPG replaces the transparent areas with a solid color.

Before you run a large job

• Test with one or two photos first and open the result at 100% zoom. Fixing a setting is cheaper than redoing ten files.
• Keep your originals. The tool never changes the source files, but a 50% copy cannot be scaled back up without a quality loss.
• Downloaded ZIP files are named with a timestamp (for example resized-images-…zip), so repeat batches will not overwrite each other.
• If the browser struggles with very large images, process them in smaller groups or reduce the output size.

Compared with desktop and cloud tools

Desktop software handles unlimited folders but needs installing and learning. Many online batch resizers upload your photos to someone else's server, add watermarks, or require an account for more than a few files. ResizeAny trades batch size for privacy and convenience: ten images at a time, entirely in your browser, with no sign-up and no watermark. If you only have one picture, use the single image resizer, or browse the 1,500+ quick presets for a ready-made size.