1
Open the image tool
Click “Open the image compressor” to go straight to the image section on ToolSee.
Free tool that runs in your browser
Compress images online — reduce file size without uploading
Is a photo too large to upload to a website or app? Need to change its format? ToolSee compresses and converts images inside your browser, with control over quality and dimensions — no server uploads.
- No sign-up
- Photos stay on your device
- JPG / PNG / WebP / HEIC
How to compress an image in 4 steps
No design software and no account on another service.
2
Choose an image
Drag a photo into the drop area or click to select it from your device. JPG, PNG, WebP and HEIC are supported.
3
Set quality and size
Pick the output format, set compression quality from 10 to 100, or change width and height while keeping the aspect ratio.
4
Download the image
Click “Convert & Download”. You will see a preview, the new format and the new file size before saving.
When do you need image compression?
A smaller image helps in more places than you might think.
- Product photos for online stores: Heavy images slow down product pages; compressing them improves the shopping experience.
- Social media: Prepare images for Facebook, Instagram and LinkedIn without losing clarity.
- Websites and blogs: Smaller images load faster, which is better for visitors and for search performance.
- iPhone HEIC photos: Convert HEIC files into a format you can use on Windows or upload to more websites.
- Email attachments: Reduce photo size before sending them, so you stay under attachment limits.
Image compression features
Full control over the result, with privacy built in.
Adjustable quality
Choose a compression level from 10 to 100 and see the new file size before saving.
Resize dimensions
Set the exact width and height you need, with an option to keep proportions and avoid distortion.
Format conversion
Convert between JPG, PNG and WebP, and use HEIC photos from iPhone directly.
Transparency support
PNG and WebP keep transparent backgrounds. JPG fills transparency with white because the format does not support it.
Local processing
Your image is processed inside your browser. Nothing is uploaded to a server or stored by us.
Mobile friendly
Compress images from an Android or iPhone browser, or from your computer.
Tips for the best size and quality
- For normal photographs, try quality 70 to 85. You will usually save a lot of space with only a small visible difference.
- For logos and images with text, use PNG or WebP at high quality so edges and letters stay sharp.
- If the image is larger than you need, resize it first. Reducing dimensions saves more than lowering quality alone.
- JPG does not support transparency. If you have a logo with a transparent background, choose PNG or WebP.
- In PNG mode, the browser does not use the quality slider; compression mainly comes from resizing or converting to WebP.
- Check the result before publishing, especially if the image contains small details or text.
Practical guide
Compress images without losing the quality that matters
Smart compression is not just lowering quality. Format, dimensions, and compression level decide whether an image looks sharp or blurry. This guide explains how to find the right balance for your use case.
Choose the format before compressing
JPG suits photographs, PNG is better for logos and transparent images, WebP is a strong choice for the web because it combines small size with good quality, and HEIC is common on iPhone but is not displayed by every browser.
If you convert a transparent PNG to JPG, the transparent background becomes white or black. Choose the format based on where the image will be used, not only on file size.
- Photos and backgrounds: JPG or WebP.
- Logos, icons, and transparency: PNG or WebP.
- Web images: WebP with a JPG fallback for older browsers.
Quality and dimensions: what controls the size?
The quality level reduces detail, while dimensions reduce the number of pixels. If an image will be displayed at 800 px wide on the web, you do not need to keep it at 4000 px. Reduce the dimensions first, then adjust quality.
Try 75–85% for photographs, and 90% or higher for logos and sharp text. Always compare the original and the compressed version at 100% before publishing.
- Web: start at 1600 px wide for a main image.
- Social media: 1080 px is often enough.
- Email: 800 px and moderate quality are usually sufficient.
Transparency and images with a background
If the image contains transparency, use PNG or WebP. JPG does not support transparency, so any transparent background becomes a single color. For logos, test the image on both a light and a dark background.
Screenshots often contain sharp text. Too much compression can make the text unreadable, so use a higher quality or PNG if the text is the most important part.
Practical use cases
- Product photos for an online store.
- Blog images and thumbnails.
- Email attachments with a size limit.
- Social media images and administrative forms.
If you have a PDF with large images, compress the images first and then use the PDF merger to assemble the document.
Pre-publish checklist
- Compare the original and compressed image side by side.
- Zoom into faces, text, and edges to spot artifacts.
- Test transparency on a light and a dark background.
- Always keep a copy of the original image.
- Use WebP with a JPG fallback if your audience uses older browsers.
- Do not upscale a small image; upscaling does not restore detail.
By the ToolSee team — last updated 23 October 2026
Frequently asked questions about image compression
Is image compression free?
Yes. The compression and conversion tool is completely free and requires no sign-up.
Are my images uploaded to a server?
No. Images are processed in your browser and are never uploaded to a ToolSee server.
Does compression reduce image quality?
Reducing file size can remove some detail, especially at very low quality settings. Use a medium or high quality level and check the result before use. Try 70 to 85 for normal photos.
Does the tool support HEIC photos from iPhone?
Yes. HEIC is decoded in your browser and converted to a usable format such as JPG, PNG or WebP.
Can I keep a transparent PNG background?
Yes, when you choose PNG or WebP. JPG does not support transparency, so it adds a white background instead.
Is there a file size limit?
There is no fixed limit in the tool, but very large images depend on your browser and device memory. If it feels slow, try a smaller image or close other apps.
Is it suitable for product photos?
Yes. You can resize and compress product images for online stores and websites. Review the result before publishing to make sure details are clear.
Can I convert JPG to WebP?
Yes. Choose WebP from the output format menu, then click Convert & Download.
Does compression reduce image dimensions?
The tool reduces quality; if you set a new width or height, the dimensions change too. If you leave the dimensions untouched, the image keeps its original width and height.
What quality should I use for product photos?
Start at 75–85% in JPG or WebP, with a width of 1200–1600 px for the main image. Check the result on a phone and make sure important details are still visible.
Is HEIC supported on every device?
The tool can process HEIC in the browser, but display support varies between browsers. For the web, convert to JPG or WebP.
More free tools from ToolSee
Every tool is free and runs inside your browser.
Ready to compress your image?
Open the tool, choose a photo, and set the quality or dimensions you need.