Bulk Image Compressor
- Free
- No upload
- No watermark
Quick answer
Point this at a whole folder of photos and it works through all of them in parallel, showing progress per file, then hands you back one ZIP when everything is done.
What it does
What the bulk image compressor does
Compressing one photo is a slider and a click. Compressing an entire event's worth of photos, or exporting a WordPress media library before a site migration, is a different problem: you need consistent settings across every file, visibility into which ones are still processing, and a way to get everything back out without downloading two hundred files one at a time.
Toolvy handles the volume with parallel Web Workers: several images are encoded at once rather than one after another, so a batch of a hundred photos does not take a hundred times as long as a single photo. Each file gets its own progress indicator and the same codecs as the single-image tools: MozJPEG, oxipng, libwebp.
When the batch finishes, everything is bundled into a single ZIP so you are not clicking save two hundred times. Failed files, if any, are flagged individually rather than silently dropped, so you know exactly what did and did not make it into the download.
Step by step
How to use it
- 01
Select a folder or multiple files
Drag a whole folder onto the page, or select many files at once from the file picker.
- 02
Set quality or a target size
Choose a single quality setting or byte target that applies to every file in the batch.
- 03
Watch per-file progress
Each image shows its own status as parallel Web Workers process the batch simultaneously.
- 04
Review any flagged files
Files that failed to decode, such as corrupted uploads, are listed separately rather than silently skipped.
- 05
Download the ZIP
Every successfully compressed image is bundled into one archive, ready to re-upload or archive elsewhere.
Your images never leave your device
A media library export or an entire event's photo folder is a much bigger liability to hand to a server than one image at a time — it is essentially your whole photographic footprint for that shoot or site in one place. Running it through parallel Web Workers on your own device means that volume of files never gets bundled up and sent anywhere, which matters more the bigger the batch gets.
- No file is ever uploaded to a server
- Works offline after the first visit
- No account, no watermark, no limits
Get better results
Format and quality tips
- 01
A single quality setting will not suit every photo equally
Busy, high-detail images compress less efficiently than plain or softly lit ones, so a batch quality of 80 might produce excellent results on some files and slightly soft ones on others. Spot-check a few of the more complex images from the batch rather than only the first result.
- 02
Use a target size for consistency, quality for speed
A byte target keeps every output file a predictable size, useful when you have a fixed hosting quota, but it means the binary search runs per file and takes a little longer than a flat quality setting applied straight across the batch.
- 03
Large batches are limited by your device, not by Toolvy
Because everything happens in your browser's memory, a batch of a few thousand phone photos may need to run in smaller groups on a machine with limited RAM. If the tab becomes sluggish, split the folder into two or three uploads instead of one enormous one.
A little more clarity
Frequently asked questions
01How many images can I compress at once?
There is no fixed cap; the real limit is your device's available memory. Most laptops handle several hundred phone photos in a single batch without issue.
02Will all my images end up the same file size?
Only if you choose a byte target rather than a flat quality setting. A shared quality setting produces varying file sizes depending on complexity, while a shared byte target produces varying quality instead.
03Can I use this to shrink a WordPress media library export?
Yes, that is a common use: export the media library, run the whole folder through at a consistent quality, then re-upload the smaller versions to cut hosting storage.
04What happens if one file in the batch fails?
It gets flagged individually in the results list rather than stopping the rest of the batch or being silently dropped, so you can identify and retry just that file.
05Does bulk compression use my file names or does it rename them?
Original file names are preserved inside the ZIP, so the download maps directly back to your source folder without manual matching.
06Is bulk compression slower per image than the single-image tool?
No, it is typically faster overall because parallel Web Workers process several images at once, even though each individual image goes through the identical encoding step.
Guides
Further reading
- Guide6 min readHow to Reduce a Photo to 100KBA 100KB cap is a hard wall on an upload form, not a suggestion. Here is the resize-then-compress method that gets you under it while the photo still looks like a photo.Read the guide
- Guide6 min readHow to Compress an Image for EmailEmail attachment limits are smaller than the number they advertise, and your recipient is probably on a phone. Here is how to make photos that always arrive and always open.Read the guide
- Guide6 min readPNG vs JPG: Which Should You Use?The rule is short: photographs go to JPG, anything with sharp edges or transparency goes to PNG. This post explains why, so you never have to guess again.Read the guide
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