What the image compressor does
The CubTools image compressor reduces the file size of your JPG, PNG, and WebP images while keeping them looking sharp. Drop in your pictures and each one is processed automatically — no upload to a server, no waiting in a queue, no account needed.
Every image gets its own card showing the original size, the new size, and the exact percentage saved, so you can see precisely what the compression achieved before downloading anything.
Compressing your images step by step
Select up to 20 images at once — they start compressing the moment you choose them. There is no start button and no batch to configure; the tool gets to work immediately and each card updates live as its image finishes.
Adjust the quality slider to taste: lower values mean smaller files, higher values preserve more detail. Changing any option re-processes everything automatically, so experimenting costs nothing. Then download images individually or grab them all as a single ZIP.
Choosing the right output format
You can keep each image's original format or convert on the fly: JPG for photos where tiny artifacts are invisible, PNG when you need transparency or crisp graphics, WebP for the best size-to-quality ratio on modern browsers.
A practical default: WebP at a medium-high quality setting shrinks typical photos dramatically with no visible difference. Switch to PNG only for images where every pixel matters, like logos or screenshots with text.
When to stop compressing
Smaller is not always better. Zoom into each result at full size and look at edges, gradients, and text — if you spot blockiness or color banding, nudge the quality back up. The savings readout tells you exactly what each step costs or gains.
For web use, aim for the smallest file that still looks perfect at its display size. A hero image shown at 1200px wide does not need the quality you would want for a print file.
What to do after downloading
Compressed images deserve the same organization as your originals. Extract the ZIP into a clearly named folder — project name plus date works well — and keep it separate from your source files. If these images are headed for a website, this is also the ideal moment to rename files descriptively, since search engines do read file names.
Before uploading anywhere, do a final spot check: open two or three images at their actual display size and confirm they look right. Then verify on the live page after upload — some platforms apply their own compression on top of yours, and knowing your starting quality helps you judge whether the platform is degrading your images further.
Steps
- Open the CubTools image compressor in your browser.
- Select up to 20 JPG, PNG, or WebP images — processing starts automatically.
- Adjust the quality slider until the size-to-quality balance looks right.
- Pick an output format per your needs: JPG for photos, PNG for graphics, WebP for smallest files.
- Review each card's original size, new size, and savings percentage.
- Download images individually or click download-all to get everything as a ZIP.
Frequently asked questions
Is the image compressor really free?
Yes — completely free, no account, no watermarks, no daily limits. All processing happens in your browser.
How many images can I compress at once?
Up to 20 images per batch. Each is processed automatically and shown on its own card with before/after sizes.
Will compression ruin my image quality?
Not if you choose sensibly. The quality slider lets you balance size and fidelity, and the live preview cards show exactly what you get before downloading.
Do my images get uploaded anywhere?
No. Everything is processed locally in your browser — your photos never leave your device.