CleanorTools
Publishing

Bulk optimization

Details

How to use Bulk optimization

What the tool does, how to run it, and what to expect from the result.

How to optimize a batch of images

To optimize images, add up to 10 files to the batch image optimizer, let it compress and resize them with sensible settings, and download the lighter results one by one or all at once. Everything runs in your browser, so the images never leave your device and there is no upload queue to wait on.

This is most useful before publishing, when files are too heavy, the page builder feels slow, or an upload form rejects oversized images. Optimizing early keeps your images readable while cutting page weight, which helps load times and Core Web Vitals.

  • Website hero images and inline article visuals
  • CMS uploads and marketplace listings
  • Profile, product, and support images
  • Small publishing batches instead of one-off manual exports

Is the batch optimizer free and private?

Yes. The batch image optimizer is free with no sign-up, no watermark, and no cost per image. You can run as many batches as you need.

It is private because all compression and resizing happen client-side in your browser. Your images stay on your device and are never sent to a server, which makes it safe for client work, internal assets, and anything you would rather not upload.

How many images can it handle at once?

The optimizer handles up to 10 images per batch, a practical limit that keeps the tool responsive on normal laptops and phones since the work runs locally rather than on a server. For small publishing sets, this is usually all you need.

For very large batches or advanced formats, server-side processing can be more efficient, but for everyday website and upload work, browser-based optimization is faster, cheaper, and more private. Just add another batch when you have more files.

Tips

Getting a better result out of Bulk optimization

Specific settings and thresholds, not general advice.

  • Optimize after you resize, never before. Every pixel you remove first is a pixel the optimizer no longer has to encode, and resolution beats quality settings every time.
  • Convert format before you tune quality. Our benchmark measured AVIF at 37% smaller than JPEG at matched quality, which is a bigger win than any slider in any format.
  • 80 to 85 is the useful quality band for JPEG and WebP on photographs. Above 90 you are paying for invisible detail; below 70 the artefacts start to show.
  • Batch means the same settings for every file, so group by content. A folder of photographs and a folder of logos want completely different treatment.
  • Keep the originals. Optimization is a one-way door for lossy formats, and the source file is what you will need when the requirements change.
Limits

What Bulk optimization does not do

The honest boundary, so you do not lose time finding it yourself.

  • It does not resize. Optimizing and resizing are separate jobs by design.
  • It cannot recover quality from an already-compressed image.
  • It applies one setting to the whole batch, so mixed content needs more than one pass.
  • It does not edit or retouch.
Reference

Terms used on this page

Short, plain-language definitions for the formats and settings above.

Editing & toolsImage compressionImage compression shrinks a photo’s file size by removing redundant or less-visible data. Lossy compression (JPEG, WebP) drops fine detail for big savings; lossless compression (PNG) keeps every pixel but saves less. It is the fastest way to make images smaller for sharing, email, or the web.GeneralWeb & SEOWeb Image CompressionWeb image compression reduces an image file's byte size for faster page loads using lossy or lossless encoding, modern formats like WebP and AVIF, correct dimensions, and responsive delivery — without unnecessary loss of visible quality.GeneralWeb & SEOCore Web VitalsCore Web Vitals are Google's standardized metrics for real-world page experience: Largest Contentful Paint (loading), Interaction to Next Paint (responsiveness), and Cumulative Layout Shift (visual stability). They factor into ranking.General
At a glance

Who Bulk optimization is for

A quick way to understand who this helps, what it solves, and where it connects next.

Best fit

People preparing screenshots, product visuals, blog images, profile photos, and simple web assets

Ideal for

Batch image cleanup before uploading to websites, CMSs, forms, marketplaces, or support tools

FAQ

Common questions

Short answers for the questions people usually have before trying a utility like this.

Is the batch image optimizer free?

Yes. The batch image optimizer is completely free with no sign-up, no watermark, and no limit on how many batches you run.

Does it upload my images?

No. The optimizer runs entirely in your browser, so your images stay on your device and are never uploaded to a server.

How many images can I optimize at once?

You can optimize up to 10 images in a single batch, which keeps the tool fast and responsive on regular laptops and phones.

Will optimizing reduce image quality?

The optimizer aims for a strong balance, shrinking file size while keeping images visually clean and readable for web use.

Does it work on mobile?

Yes. It works in any modern mobile or desktop browser because all optimization happens locally on your device.

What is the right order: resize, convert, or compress?

Resize first, convert second, compress last. Resolution is the biggest lever, format is the second, and the quality slider is the smallest. Doing it in the other order wastes most of the saving.

What quality setting should I use for a batch?

80 to 85 for photographs in JPEG or WebP. Above 90 you pay for detail nobody sees; below 70 the artefacts become visible on skies, skin and flat colour.

Should I convert everything to AVIF?

If the destination takes it, it is the biggest single win available: our benchmark measured AVIF at 37% smaller than JPEG at matched quality. But email clients and older software still refuse it, so keep a fallback.

Can I optimize photos and logos in the same batch?

You can, but you should not. One setting is applied to every file, and photographs and flat graphics want opposite treatment. Split them into two passes.

Should I keep the original files?

Always. Lossy optimization is a one-way door, and the original is what you will need when the size requirement, the format or the platform changes.

Recommendations

You Might Also Like

Nearby tools from the catalog that fit the same job or workflow.

APNG
ImageAnimation

APNG Optimizer

Shrink animated PNG files

Rebuild animated PNG files in the browser to reduce weight, merge duplicate frames, and cap frame rate.

AVIF
ImageAVIF

AVIF Compressor

Compress still AVIF

Optimize a still AVIF with focused presets for lighter delivery without switching away from AVIF.

Q
ImageJPEG

Compress JPEG

Tune JPEG quality

Shrink a JPG with a real quality slider, plus chroma subsampling and progressive output, in the browser.

OPT
ImageGIF

GIF Optimizer

Shrink animated GIFs

Optimize one animated GIF in the browser with presets for palette, FPS cap, and lighter output size.

CMP
ImageSmaller files

Image compression

Shrink image file size

Shrink image files without making them feel visibly broken, soft, or over-processed.

WOPT
ImageWebP

WebP Optimizer

Shrink WebP files

Optimize still or animated WebP files with lighter browser-first presets for delivery and embeds.

Cleanor app

Do it all on your device

Cleanor puts these tools in one app: compress and convert images, video, and audio, work with PDFs, and scan text right on your device. Plus free up storage and clear inbox clutter with Email Cleaner. Start with a free trial.

  • iPhone
  • Android
  • Macsoon
  • Windowssoon
Get it on the App StoreGet it on Google PlayAll platforms & pricing