Batch Image Compressor
Drop a stack of images, convert them all to WebP or JPEG, cap the width and adjust quality, then download one ZIP.
How to use
- Choose or drop several images. Processing starts right away with the current settings.
- The output format sets the extension and the encoder. WebP is usually smallest, JPEG is safest for old software, PNG keeps transparency.
- Max width controls resolution. Any image wider than the value scales down proportionally. 1600 fits most uses, and 1200 saves about half again.
- Quality applies to WebP and JPEG only. 0.75 is a good daily default, and text screenshots should stay at 0.6 or above.
- Download everything as a ZIP, or save files one by one. The suffix you set is added to each filename.
FAQ
Are my images uploaded?
Why did my animated GIF become a still image?
Can I hit an exact file size target?
Why did a file get bigger?
How to use
- Pick a batch
Click the dashed area to select several files, or drag a folder of images in. The cap is 30 files, and anything beyond is trimmed with a notice.
- Choose a format
WebP is smallest for web and documents. JPEG opens anywhere. PNG keeps transparency for icons and screenshots.
- Set width and quality
Max width controls resolution and scales larger images down. Quality applies to WebP and JPEG only. 0.75 suits most work, and text images should stay at 0.6 or above.
- Read the per-file result
Each row shows the before and after size plus a percentage. A negative number means that file was already compressed hard, so keep the original.
- Download one ZIP
Press Download ZIP to take everything at once with your suffix applied. Individual downloads are there when you only need a few.
About this tool
Single-image compressors are everywhere. The real friction starts at twenty files. Writing docs, preparing product shots or adding images to a blog means dragging, waiting and downloading one file at a time. A batch tool turns that into pick a set, set the options once, take one archive. The encoding work is identical, and the repetition is what disappears. The larger the batch, the more time it saves and the fewer chances to miss a file.
The page decodes each image into a canvas, scales it to the max width and lets the browser encoder produce WebP, JPEG or PNG. A white fill is available for JPEG so transparent areas do not turn black. Results stay in memory until you package them. The archive uses ZIP store mode, which writes files without recompressing them, so packaging is close to instant. Your suffix is applied to every filename, including non-Latin names.
How it works
There is no server queue in a browser batch job. Every image is fully decoded, and a 4000×3000 photo occupies about 48MB once decoded. A dozen waiting at once can trigger memory reclamation on a phone, which shows up as stutter or a blank page. This page works through files one by one, releases the canvas after each, and caps total pixels at 40 million to keep the peak down. Batches of about ten files are the safest habit.
The ZIP uses store mode, which packages without a second compression pass. Images are already compressed, so deflate typically saves under three percent while costing several times the CPU. The stored archive is slightly larger but builds almost instantly and extracts faster. Filenames are written as UTF-8, so non-Latin names survive the trip. The download opens with any standard unzip tool, and the originals on disk are never modified at all.
When to use it
- A product upload
A shop adds 24 photos and the platform caps each at 500KB. Set max width 1600 and quality 0.75, convert the set once, then lower quality only on the few rows still over the limit. Doing that file by file would take an afternoon and still risk a missed attachment.
- Blog illustrations
A long post needs a dozen screenshots, and the originals weigh one or two megabytes each. Convert to WebP at 1200 pixels wide and the whole article drops to about a fifth of its original image weight. Readers on a phone load the page faster and stop scrolling through grey placeholders.
- Sending assets to a colleague
A designer exports a pile of PNGs but the mail attachment limit is tight. Convert to JPEG with a white fill, pack one ZIP, and the message goes through while the other side just unzips. Nobody has to ask for the originals again.
Tips & tricks
- Set the width before touching quality. Resizing saves far more bytes than a lower quality slider and keeps the image cleaner.
- Use WebP 0.75 for product and article images, JPEG 0.8 for email and old software, and PNG for transparent icons.
- Trim the batch first. Decoding thirty images at once uses a lot of memory, and older phones feel it first.
Things to watch
- Dropping animated GIFs
A canvas reads only the first frame, so animation disappears. Keep animated files out of the batch and use a frame-aware tool when motion matters. Otherwise the file ships as a still and the mistake only shows up after sending.
- Forgetting the white fill
A transparent image converted to JPEG turns black or mottled, and icon edges show it first. Leave the white fill on, or export PNG instead. Logos and transparent icons are the usual victims. Open one output before sending the batch, since the problem is obvious at full size.
- Loading too many large photos
Decoding dozens of high-resolution photos at once exhausts memory, and phones can crash the tab. Work in batches of about ten and watch whether the list keeps updating. If it freezes, refresh and start with fewer files instead of adding more to the same page.