Free Bulk Image Compressor: Smaller Files, Same Format
Compress JPG, PNG, WebP, AVIF, GIF, BMP, and HEIC images in bulk without changing formats. Set a quality level, a max file size target, or both, and your images compress instantly in your browser. Nothing uploaded. Nothing stored.
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0 imágenes añadidasCompress Your Images in 3 Steps
No account, no install, no queue. Drop your images in and the compressed versions are ready to download.
- Step 1
Drop your images in
Drag files onto the page, click to browse, or drop in a ZIP and every supported image inside is pulled out. JPG, PNG, WebP, AVIF, HEIC, GIF and BMP all work, mixed together in the same batch.
- Step 2
Adjust if you want to
Pick a quality percentage, or switch to Max size and give it a KB budget. The compressor works out the best quality that fits, file by file, and leaves your formats alone.
- Step 3
Download your compressed files
Conversion starts on its own, so there is usually nothing to press. Batches over 40 wait for one click so nothing runs away with your machine. Download files one at a time or take the whole batch as a single ZIP.
Compress Images Without Changing Formats
Most image tools force you to convert formats to get smaller files. This compressor works differently. It reduces file size while keeping your images exactly as they are: JPG stays JPG, PNG stays PNG, WebP stays WebP. You control how aggressively it compresses. When a size limit is set, the tool reduces quality first, then reduces dimensions only if it has to. Giving you the best possible image at your target size.
Compress by Quality Percentage
Set a quality percentage from 1 to 100. Lower quality means smaller files. At 75% the difference is virtually invisible to the human eye, but file sizes can drop by 40-70% compared to the original. Ideal for web uploads, blog images, and email attachments where visual quality still matters.
Compress to a Max File Size (KB)
Set a maximum output size in KB and the tool guarantees the result stays under it. It reduces quality first to reach your target. If quality reduction alone isn't enough, it also scales down the image dimensions, so you always get the result at your exact size limit, with the best possible quality at that size.
Every Feature You Need. Nothing You Don't.
Most image compressors are blunt instruments. Drop a file, get a compressed file, no control. SmallerImages gives you precise control over quality, file size, format, and output for every image in your batch.
Bulk Compression: 150 Images
Upload and compress up to 150 images in a single batch. Drag in a ZIP archive and every image inside is extracted and compressed automatically. No per-file limits mid-batch.
100% Private & Secure
Every compression runs locally using client-side JavaScript. Nothing is uploaded to any server. No one can see, access, or store your images. Including us.
Max File Size Target (KB)
Set a hard ceiling on output file size. The tool reduces quality to hit your target, and if quality alone isn't enough, it scales down image dimensions too. The result is always the best quality possible at your exact size limit.
Quality Percentage Control
Set compression quality from 1% to 100%. The default 75% delivers strong compression with virtually no visible quality loss. Lower for maximum size savings, higher for critical images where detail matters.
Keep Original Format
By default the compressor preserves each image's original format. JPG stays JPG, PNG stays PNG. Or choose a target format to convert and compress in one step. GIF, BMP, and HEIC are output as WebP when the original format can't be created by the browser.
ZIP Upload & Download
Upload a ZIP containing your entire image library. Download all compressed files as a single ZIP in one click. Perfect for batch workflows where you need to process dozens of images at once.
All Major Formats Supported
JPG, PNG, WebP, AVIF, GIF, BMP, and HEIC all supported as input. Output to the same format or choose JPEG, PNG, WebP, or AVIF. Need format-specific conversion? See our dedicated PNG to WebP and JPG to WebP tools.
Works on Every Device
Windows, Mac, Linux, Chromebook, iPhone, iPad, Android. Any modern browser runs this tool. No downloads, no plugins, no OS-specific limitations.
Smart Dimension Reduction
When quality reduction alone can't hit your target file size, the tool automatically scales down image dimensions as a secondary step, so you always get the smallest possible file at your exact KB limit, without manual resizing.
How SmallerImages Compares
Here's how our free bulk image compressor stacks up against typical online tools.
| Feature | SmallerImages | Typical Compressor |
|---|---|---|
| Bulk compression (up to 150 files) | Yes | No 5-20 file limit |
| Browser-based (no server uploads) | Yes | No Files uploaded to server |
| Max file size target (KB) | Yes | No |
| Dimension reduction as fallback | Yes Automatic | No |
| Keep original format | Yes | Sometimes |
| ZIP upload & download | Yes | No |
| HEIC & AVIF input support | Yes | No |
| Quality control (1-100%) | Yes | Limited presets |
| 100% free, no signup | Yes | Freemium / ads |
| Ad-free experience | Yes | No |
Who Uses a Bulk Image Compressor?
Anyone who works with images regularly runs into the same problem: files are too big for email, too slow to upload, or too heavy for a web page. Here's where bulk compression makes the biggest difference.
Web Developers & Site Owners
Uncompressed images are the single biggest cause of slow websites. Google PageSpeed Insights flags oversized images in almost every audit. Compress your entire media library in one batch and cut page load times without touching a line of code.
E-commerce Store Owners
Product pages with dozens of uncompressed images load slowly and lose sales. Set a max file size per image, compress your entire product catalog in one go, and upload. Faster product pages mean higher conversion rates.
Email Marketers & Newsletter Creators
Email clients have strict attachment size limits and slow down with heavy images. Set a max file size of 100-200 KB per image and compress your entire batch before inserting into your newsletter template.
Designers & Creative Agencies
Clients regularly ask for "web-ready" versions of assets alongside print-resolution originals. Compress your entire design export folder in one batch and deliver both versions without manually re-exporting from your design tool.
Social Media Managers
Platforms like Instagram, Facebook, and LinkedIn re-compress your images when you upload them. Pre-compressing gives you control over what gets submitted, so the platform's algorithm starts from a clean, already-optimised file rather than a bloated original.
WordPress & CMS Publishers
Every image uploaded to WordPress becomes multiple resized versions that consume server storage. Compressing images before uploading reduces the size of every generated thumbnail. Less storage used, faster media library, faster site. All from compressing before you click Upload.
What People Say About Bulk Compression
Real feedback from people compressing images every week: agencies, store owners, developers, and photographers.
Clear about what it did to each file. Compressed, already optimised, or skipped. No mystery.
Compression without format conversion is exactly what I needed. Our CMS expects specific formats and this respects that instead of helpfully deciding for me.
Works on a managed work laptop where I cannot install software. That alone makes it worth bookmarking.
The ZIP download is what makes big batches practical. Nobody wants to click through 100 individual downloads.
Runs entirely locally, which means I can compress unreleased campaign assets without a legal review first.
Average saving across our catalogue was around 70%. Bandwidth bill dropped the following month.
Being able to choose between a quality percentage and a hard size limit covers both jobs. Quality for hero images, size cap for anything going into email.
Compressed 140 product photos in one go and every single one came in under my 200 KB budget. Nothing else free handles that volume without splitting it into batches.
Used a paid Kraken.io account before. This is faster for bulk work because there is no upload step and no processing queue.
Clear about what it did to each file. Compressed, already optimised, or skipped. No mystery.
Compression without format conversion is exactly what I needed. Our CMS expects specific formats and this respects that instead of helpfully deciding for me.
Compressed a batch on my phone while travelling. Not something I expected to be possible.
Bulk Image Compression, Without Changing Your Formats
How the compressor decides what to discard, what the two modes actually do, and when to use each one.
Most compressors make one decision for you: they pick a format, apply a fixed preset, and hand back whatever comes out. That is fine until your content management system expects PNG and receives WebP, or a print supplier rejects the file. This tool leaves the format alone by default. A JPG stays a JPG, a PNG stays a PNG, and only the bytes change.
There are two ways to control that. Quality mode applies a single percentage across the batch, which is the right choice when you care about how the images look and have no particular size target. Maximum size mode works the other way around: you give it a budget in kilobytes and it searches for the highest quality that fits, adjusting per file. A simple graphic might land at quality 90 and a detailed photograph at 60, and both come in under your limit.
The compressor also refuses to make a file larger. If an image is already well optimised, re-encoding it would add bytes rather than remove them, so it keeps the original and tells you why. That sounds obvious and is surprisingly rare, including among paid tools.
Nothing is uploaded. The compression runs in your browser using the same codecs the browser already ships for displaying images, plus a bundled AV1 encoder for AVIF output. You can disconnect from the network mid-batch and it carries on.
Need to Convert Formats Too? We've Got You.
Every conversion path has its own page with defaults already set for that pair. The tool behind all of them is the same one you have been using: it accepts JPG, PNG, WebP, AVIF, HEIC, GIF and BMP, reads ZIP archives, and handles up to 500 images in a single batch.
Conversion runs in your browser using your own processor, so nothing is uploaded, nothing is queued behind other people, and there is no account, no watermark and no daily cap. Close the tab and the files are gone from memory; they were never anywhere else.
If you need a smaller file rather than a different format, the image compressor keeps your originals and works to a quality level or a size in kilobytes. To change dimensions, the image resizer handles fit, fill and crop, or stretch across a whole folder at once.
Frequently Asked Questions
Quick answers about the SmallerImages bulk image compressor.
Is it safe to compress my images on SmallerImages?
What image formats does the compressor support?
What does Max File Size (KB) do exactly?
What quality percentage should I use?
Can I compress images without changing the format?
How many images can I compress at once?
What happens to GIF, BMP, and HEIC files?
Does compression reduce image dimensions?
Can I upload a ZIP file containing images?
Is SmallerImages completely free?
Your Images Are Bigger Than They Need to Be
Every oversized image is a slower page load, a failed email attachment, a rejected upload. Compress your entire batch in seconds. Free, private, no uploads, no limits.
Compress Images Now