Tools/Image/Bulk Image Compressor

Bulk Image Compressor

Shrink the file size of your JPG and PNG images with an adjustable quality slider. Compress a single image or a whole batch at once — multiple files download as a single ZIP.

Batch or Single: Compress one image or many at once
Adjustable Quality: Fine-tune the size vs. quality tradeoff
Private: Images are compressed locally, never uploaded
Free: No limits, no watermark

Why compress images in-browser?

Compressing dozens of photos one at a time on a typical online tool means dozens of individual uploads and downloads. Karvics compresses your whole batch using the browser's built-in Canvas API and zips multiple results into one download — and because nothing is uploaded, it works just as well for personal photos as it does for anything you'd rather not send to an unfamiliar server.

What this tool controls

Quality slider: Trade off file size against visual fidelity on a 10-100% scale
Batch processing: Compress many images in one pass, downloaded as a ZIP
Format-aware output: PNGs stay PNG (lossless-friendly), everything else compresses as JPG
Size comparison: See the total size reduction after compressing

How to Use

Upload one or more JPG, PNG, or WEBP images
Adjust the quality slider
Click "Compress"
Download the compressed image, or a ZIP for multiple files

💡 Pro Tips

Start around 70% quality — it typically cuts file size substantially with no visible difference at normal viewing sizes.
Photos with lots of fine detail (foliage, fabric texture) show compression artifacts sooner than simple graphics — preview the result before going below 50%.

Glossary

Compression Quality: A setting that trades visual fidelity for smaller file size — lower quality produces smaller files with more visible artifacts.
Lossy Compression: Reducing file size by permanently discarding some image data, usually imperceptible at high quality settings but visible at low ones.
Compression Artifact: A visible distortion (blockiness, blurring, or color banding) introduced by lossy compression, more noticeable at lower quality settings.
Canvas API: A browser API for drawing and manipulating images in JavaScript, used here to re-encode images entirely client-side.

Frequently Asked Questions about Bulk Image Compressor

Yes. Upload as many images as you like — they'll be compressed in one batch and downloaded as a single ZIP file. A single uploaded image downloads directly instead.

No. Compression happens entirely in your browser using the Canvas API. Your images are never sent anywhere.

Start around 70% — it usually gives a large size reduction with minimal visible quality loss. Lower it further for smaller files, or raise it if you notice artifacts.

It can, since compression is lossy — lower quality settings discard more image data for a smaller file. At 70% and above the difference is rarely visible at normal viewing sizes.

Yes, PNGs are supported, though PNG compression has less room to shrink than JPG since PNG is already a lossless format — expect smaller size reductions than with photos.

Related Tools

Explore more tools from this category to enhance your workflow

Image Editor & Cropper

Crop, resize, rotate, flip, and add watermarks to images online. Secure, client-side processing.

Image Metadata Remover

Remove EXIF, GPS, and device metadata from photos. Lossless for JPEG, secure client-side cleaning.

Bulk Image Format Converter

Convert images between JPG, PNG, and WEBP online, one at a time or in bulk. Free, secure, client-side processing.

Favicon Generator

Convert images to favicons in multiple sizes with HTML tags. Secure, client-side generation.