Best Image Compression Tools: Compress JPG and PNG Online
The right image compressor can reduce file size without making your photos, screenshots, or graphics look poor. Compare the best tools by quality, privacy, formats, batch support, and ease of use.
Large image files slow down pages, consume bandwidth, and make websites feel less responsive—especially on mobile connections. Image compression helps by reducing the amount of data a browser must download while preserving an acceptable visual result.
There is no single “best” compressor for every image. A photographer may want fine-grained quality controls. A marketer may want to compress 20 JPGs quickly. A developer may need browser-based privacy or an API. The best choice depends on the image format, the target dimensions, the acceptable quality loss, and how many files you need to process.
Which image compression tool is best?
For most people, TinyPNG is the easiest starting point. It supports modern formats such as AVIF and WebP alongside PNG and JPEG, and its online tool currently allows up to 20 images at a maximum of 5 MB per image.[1] If you need local processing because the images are private, use Squoosh instead.[2] If you need more visible controls for resizing, metadata, file naming, and compression mode, try Compressor.io.[3]
These recommendations are based on the tools’ published features, not a claim that one compressor produces the smallest file for every image. Compression results vary by source dimensions, image detail, format, quality setting, and whether transparency must be preserved.
Best image compression tools compared
| Tool | Best for | Formats and notable features | Privacy / limits |
|---|---|---|---|
| TinyPNG | Fast, simple optimization | AVIF, WebP, PNG, JPEG; automatic conversion; online batch uploads | Online upload; up to 20 images and 5 MB each on the current web compressor |
| Squoosh | Privacy and visual comparison | Browser-based codec controls, side-by-side inspection, local processing | Images stay on your device; controls can be more technical |
| Compressor.io | Control and file preparation | JPEG, PNG, SVG, GIF, WebP; resize, rename, EXIF options, lossy/lossless/custom | Online tool; max file size shown as 10 MB |
| ImageCompressor | Private, no-signup browser compression | JPEG, PNG, WebP, GIF, SVG; quality slider and before/after comparison | Browser-only processing; says no uploads and no daily limits |
| iLoveIMG | Simple batch compression and cloud workflow | JPG, PNG, SVG, GIF; compress multiple images; Drive and Dropbox import | Cloud upload workflow; free and premium limits may vary |
| ImageOptim | Mac users and developer automation | Mac app plus API; metadata removal, resizing, responsive variants, JPEG/PNG optimization | Desktop and paid API options; suited to repeatable workflows |
1. TinyPNG: best for quick online compression
Why choose TinyPNG?
TinyPNG is a strong default when you want a simple drag-and-drop workflow. Its official page lists compression for AVIF, WebP, PNG, and JPEG, plus automatic conversion options and a current web limit of up to 20 images at 5 MB each.[1]
It is useful for blog images, product photos, thumbnails, and social assets when you do not need to tune every codec setting. The trade-off is that the online workflow involves uploading files to a service, so private or sensitive images deserve extra care.
Choose it when: speed and simplicity matter more than advanced control. Before downloading, compare the compressed version with the original and check small text, edges, gradients, and transparency.
2. Squoosh: best for privacy and manual control
Why choose Squoosh?
Squoosh describes itself as an image optimizer that lets you compress and compare images with different codecs. Its privacy documentation states that images never leave your device because processing happens locally in the browser.[2]
This makes it a good option for unpublished product designs, screenshots containing internal information, client work, or any image you prefer not to upload. It also gives you a useful visual learning experience: adjust settings, inspect the differences, and save the version that balances size and quality.
Choose it when: privacy and control are more important than one-click automation. It is especially useful when choosing between JPEG, WebP, AVIF, and different quality levels.
3. Compressor.io: best for resizing and compression controls
Why choose Compressor.io?
Compressor.io supports JPEG, PNG, SVG, GIF, and WebP. Its interface exposes options for resizing, keeping EXIF data, fixing orientation, renaming files, choosing quality, and selecting lossy, lossless, or custom compression. The page currently shows a 10 MB maximum file size.[3]
This is convenient when you want to prepare files in one pass instead of resizing in one tool, compressing in another, and renaming manually afterward. Its extra controls also make it easier to build a repeatable workflow for a folder of marketing assets.
Choose it when: you need format breadth, resizing, or settings beyond an automatic compressor. Remember that “lossless” does not always mean the file will become dramatically smaller; it preserves more information, so the result depends on the source.
4. ImageCompressor: best for private, unlimited browser use
Why choose ImageCompressor?
ImageCompressor says all processing occurs in the browser using WebAssembly, with no server uploads, no registration, and no daily limits. It includes a quality slider, comparison view, and format-specific guidance.[4]
The tool’s guidance is useful for choosing formats: PNG8 can work well for graphics with limited colors and transparency, while photographs and smooth gradients may be better suited to JPEG or WebP. Treat format recommendations as a starting point and inspect the actual output.
Choose it when: you want a straightforward privacy-focused browser tool without account friction.
5. iLoveIMG: best for easy batch compression and cloud imports
Why choose iLoveIMG?
iLoveIMG’s compression page supports JPG, PNG, SVG, and GIF and is designed to reduce the file size of multiple images at once. It also exposes imports from Google Drive and Dropbox in its workflow.[5]
It is a convenient choice for a content team that already stores campaign assets in cloud storage and wants a familiar, low-friction interface. Because the workflow involves uploading files, check whether the images contain confidential information and review the service’s current terms and limits for your use case.
Choose it when: batch simplicity and cloud access are more important than local-only privacy.
6. ImageOptim: best for desktop and automated workflows
Why choose ImageOptim?
ImageOptim provides a Mac app and a web API. Its published features include metadata removal, resizing, responsive image variants, compression tuned for high-DPI displays, and optimization for JPEG and PNG workflows.[6]
This is a better fit for designers, developers, and teams that repeatedly process images rather than compressing one or two files occasionally. The API can help automate variants for srcset and <picture> implementations, while the desktop app is useful for local batch work on a Mac.
Choose it when: image optimization is part of a production pipeline, CMS, e-commerce catalog, or application rather than a one-time task.
How to compress a JPG or PNG without visible quality loss
- Start with the right dimensions. If an image will display at 1200 pixels wide, do not upload a 6000-pixel original and expect compression alone to solve the problem. Resize first or use a tool that combines resizing and compression.
- Choose the right format. JPG is usually suitable for photographs. PNG is useful for transparency, sharp interface screenshots, logos, and graphics with limited colors. WebP or AVIF may reduce size further when your website supports them.
- Choose lossy or lossless deliberately. Lossy compression usually produces smaller files with some discarded detail. Lossless compression preserves the image data but may deliver a smaller reduction.
- Compare at 100% zoom. Inspect faces, fine text, hair, edges, gradients, and transparent areas. A file that looks fine as a thumbnail can show artifacts when enlarged.
- Keep the original. Save a master copy and treat the compressed file as an export. Repeatedly recompressing a lossy JPG can compound artifacts.
- Use descriptive filenames and alt text. Compression improves delivery; it does not replace accessibility or image SEO basics.
JPG vs PNG: which should you compress?
Use JPG for photographs and complex scenes. It is designed for continuous-tone images and generally becomes much smaller when saved at a reasonable quality level. Too much compression can create blockiness, ringing around edges, and color smearing.
Use PNG for transparency, crisp text, logos, icons, and screenshots. PNG can be inefficient for large photographs because it preserves more information than a photo needs. If a PNG is a photo without transparency, compare it against WebP or JPG rather than assuming PNG is the best source format.
Consider WebP or AVIF for modern websites. Test browser support and your CMS/CDN setup. Keep a fallback when your audience or platform requires it.
Does image compression help SEO?
Compression can support SEO indirectly by reducing the amount of data a page must load and helping improve the experience for visitors. Image compression is not a guarantee of higher rankings, and it should be combined with responsive sizing, lazy loading where appropriate, correct dimensions, accessible alt text, and a stable layout.
web.dev’s image course frames smaller images as a way to improve load times and teaches image optimization as part of building fast, accessible websites.[7] The practical goal is not the smallest possible file at any cost; it is the smallest file that still looks right at the size and context where it will be used.
Common image compression mistakes
- Compressing before resizing: a 5000-pixel image may remain unnecessarily large even after quality reduction.
- Using PNG for every image: photographs often benefit from JPG, WebP, or AVIF.
- Chasing a percentage: “90% smaller” is not useful if text becomes unreadable or detail disappears.
- Removing all metadata blindly: metadata can include privacy-sensitive GPS details, but it may also contain color-profile information your workflow needs.
- Uploading confidential files without checking privacy: use local browser tools for sensitive images unless you understand the service’s handling.
- Forgetting responsive images: do not send a desktop-sized file to a small mobile slot when a smaller variant would look identical.
Frequently asked questions
What is the best free tool to compress JPG and PNG online?
TinyPNG is a good general starting point for simple online compression. Squoosh or ImageCompressor is a better choice when local browser processing and privacy matter more. Compressor.io is useful when you need resizing and more explicit settings.
Does compressing a PNG reduce quality?
It can, depending on the method. Lossless PNG optimization preserves the image data. Palette reduction or conversion to another format can reduce file size more but may change colors, transparency behavior, or fine details.
Should I compress images before uploading them to WordPress?
Usually yes, especially when you can resize them to the largest display size you need before upload. Also check whether your WordPress plugin or CDN performs additional optimization so you do not create unnecessary duplicate processing.
Which tool is safest for private images?
Use a tool that clearly processes images locally, such as Squoosh or ImageCompressor according to their published pages. For sensitive material, review the current privacy documentation and avoid uploading files to an online service unless its handling is appropriate for your situation.
Conclusion
The best image compression tool is the one that matches the job. Use TinyPNG for speed, Squoosh for privacy and codec control, Compressor.io for resizing and file preparation, ImageCompressor for local browser compression, iLoveIMG for simple batch workflows, and ImageOptim for desktop or automated pipelines.
Whatever tool you choose, use the same quality process: resize to the real display dimensions, select a suitable format, compress, compare the output at 100%, preserve the original, and test the result on the page where visitors will see it.
