Free Image Compressor & Resizer
Compress images to a maximum KB size, resize to exact dimensions, and crop photos or signatures locally. Compare JPG, PNG and WebP; download files or a batch ZIP.
1. Choose images
Drop files here or use Choose Files. Up to 30 images, 10 MB each, 50 MB total, 24 megapixels and 16,000 pixels per side. MB = 1,000,000 bytes. Output: up to 8,000 pixels per side and 24 megapixels.
Images stay on your device. HEIC/HEIF decoding loads only when needed. Animated PNG/WebP and HEIF sequences export one still frame; animation is not preserved. GIF is unsupported.
No images selected.
2. Set your requirements
New images use these defaults. Choose an image above to set an individual override.
Preview crop and padding
Select an image and adjust the crop position with the labeled sliders or arrow keys.
Default: keep original format and dimensions; JPEG/WebP quality 80%. PNG quality does not apply.
Idle
3. Compare and download
No compressed images yet.
Inspect image detail
The overlay aligns the original to the output geometry for comparison. Scroll to inspect at 100% or higher. Crop and resize can change pixels.
How to use the Image Compressor & Resizer
- Choose images and wait for validation. Rejected files stay visible. To continue with valid images, select Process valid files or remove rejected files.
- Choose Quick compression or Meet an upload requirement. Defaults keep original format and dimensions. In requirement mode set a maximum of 20, 50, 100 or 200 KB, or a custom size; 1 KB means 1,000 bytes.
- Choose original dimensions, maximum width, or exact width and height with crop or padding. Review the crop preview and background color. Choose an individual image in Settings for to override batch defaults.
- Process pending images. Review actual bytes, final dimensions and requirement status. Compare details at 100% zoom, retry one image, and download individual files or a ZIP.
Practical example
For a signature with a 300 × 100 pixel requirement and a 20 KB maximum, choose JPEG, exact dimensions, crop to fit and the 20 KB preset. Adjust crop position so the signature stays visible, then process. An output of 18,400 bytes passes the maximum; 22,100 bytes does not. These numbers illustrate the check, not a guaranteed result.
Plan your document workflow
Read the image and PDF preparation guide to choose the order of compression, conversion and merging and check the final output.
What inputs and outputs are supported?
| Input and limits | JPG, PNG, WebP and supported HEIC/HEIF variants; 30 images, 10,000,000 bytes each, 50,000,000 bytes total; 24 megapixels and 16,000 pixels per side |
|---|---|
| Output | JPG, PNG or WebP; individual files or ZIP; up to 8,000 pixels per side and 24 megapixels; current results limited to 100 MB |
Limits, assumptions and troubleshooting
JPEG/WebP target mode searches integer encoder-quality steps from your minimum to 100, measuring actual bytes at each attempt. The highest-quality candidate found within the limit is used; quality percentages are encoder settings, not a measured percentage of retained detail. PNG uses lossless browser re-encoding and can retain a smaller unchanged, still original PNG; it is not a specialized PNG optimizer and cannot promise a target size. Smaller dimensions require permission, are tried in at most eight reductions, and are unavailable while exact dimensions are fixed. Crop and padding avoid distortion. Enlargement requires permission and adds no detail. PNG/WebP preserve alpha; JPEG flattens onto your chosen background. Animation and multi-image HEIF export one still image. Canvas output generally drops metadata; an unchanged original PNG may retain it. Color profiles, HDR and unusual HEIF variants may render differently or be unsupported. Encoding support depends on your browser; formats never change silently.
Compression, dimensions and batch capabilities
On a small screen, scroll these tables sideways to read every column.
| Task | Controls and result | Conditions |
|---|---|---|
| Maximum file size | 20, 50, 100 or 200 KB presets and a custom maximum; actual output bytes | 1 KB = 1,000 bytes. JPEG/WebP quality search is bounded. A target may be impossible. |
| Specified dimensions | Original dimensions, maximum width, or exact width and height | Crop or pad instead of stretching; width/height editing can lock a ratio. |
| Photo and signature crop | Horizontal and vertical crop controls with a preview; selectable background | Check your upload instructions. General presets do not certify portal compliance. |
| Bulk image compression | Batch defaults, per-image overrides, retries, cancellation, individual downloads and ZIP | 30 files; 10 MB each; 50 MB input total. Up to 100 MB of current results in memory. |
| Comparison | Paired previews, an original/output overlay slider and 100–400% zoom | The original is aligned to the chosen output geometry for inspecting encoding changes. |
| Privacy | Local image processing; optional settings saved locally | No image uploads, content analytics, required login or installation. |
JPG, PNG and WebP compression and conversion
| Format | Encoding here | Transparency | Typical use |
|---|---|---|---|
| JPEG / JPG | Lossy, adjustable quality | Flattened onto your selected background | Photos and upload forms that require JPG |
| PNG | Lossless rendered-pixel encoding; no adjustable quality | Preserved; transparent padding optional | Logos, screenshots and text where larger files may be acceptable |
| WebP | Lossy, adjustable quality | Preserved; transparent padding optional | Website images when the destination supports WebP |
Keep original format applies to supported JPG, PNG and WebP. To convert a PNG photo to JPEG, explicitly select JPEG and a background color. Conversion alone may increase file size. Lossless PNG encoding does not make a resize lossless: removing pixels loses information.
Choosing sizes for website images and upload forms
For a website image, try WebP at a maximum width of 1,600 pixels and inspect the output before publishing. For email, the 200 KB preset is a starting point, not an attachment limit guarantee. For a signature, first copy the required pixel dimensions and maximum bytes from the upload instructions. Then choose crop or padding so text stays legible. Small file sizes, fixed dimensions and high minimum quality can conflict.
A cancelled batch keeps already completed outputs. Adding a selection over the file-count or byte limits keeps existing work. Changes to settings invalidate only affected outputs; a retry processes one image. Rejected files remain visible when you opt to process valid images. The ZIP includes current outputs, including outputs clearly labeled as not meeting every requirement.
If your browser cannot export a selected format, choose another format explicitly. If HEIC decoding fails, export a JPG or PNG copy using your device. Low-memory phones may need smaller images or fewer files even within the stated limits. One image is decoded at a time; an active browser encode may finish before cancellation takes effect in the fallback path.
HEIC decoder notices and corresponding source: local decoder version and licenses. Processing uses a separate, replaceable decoder from heic-to and libheif.
Is my data private?
Input processing and output creation run on your device. This tool does not upload inputs, filenames or outputs, and analytics are disabled. The page loads normal website styles and fonts. Reset releases the current work; download a copy before leaving. Optional local saving stores batch settings only. Images, filenames, previews and results are not saved. Uncheck Save batch settings to remove saved settings.
Provided by Toolcross. Read our privacy policy or contact us with a reproducible issue. Updated .
Frequently asked questions
How can I compress an image under 50KB?
Choose Meet an upload requirement, set 50 KB and choose JPEG or WebP with a minimum acceptable quality. Process and check that the actual output is at most 50,000 bytes. For a strictly under-50KB rule, use a slightly smaller custom maximum, such as 49.9 KB. If no candidate meets it, permit smaller dimensions or change a constraint; success is not guaranteed.
How can I resize a signature to specific dimensions?
Choose Exact width and height, enter the required pixels and select Crop to fit or Fit with padding. Adjust the crop sliders and inspect the preview. For example, a 300 × 100 pixel signature can use a white JPEG background and a 20 KB maximum; inspect legibility and the reported requirements before uploading.
Does compression reduce image quality?
JPEG and WebP exports here are lossy. Lower encoder quality can remove fine detail or introduce artifacts; compare text and edges at 100% zoom. PNG encoding is lossless for the rendered pixels, but resizing, cropping, color conversion and transparency flattening change image information. A quality value of 80 is not a promise of 80% retained detail.
Why did my PNG become larger?
Your source may already use a more efficient PNG encoding. Browser lossless re-encoding, padding or changing formats can increase bytes. For example, compare a 12 KB original against a 16 KB output; download the original if the transformation is unnecessary. PNG has no JPEG-style quality slider.
Are my images uploaded?
No. Images, filenames, previews and outputs remain on your device. The page loads website assets and, for HEIC, a local decoder. Image content is not sent to those dependencies or analytics. Optional saving stores batch settings only; there is no required login or installation.
Can I compress multiple images together?
Yes. Choose up to 30 images within 10 MB per file and 50 MB total. Use batch defaults or individual overrides, then download separate files or a ZIP. For example, keep one transparent logo as PNG and export a photo as WebP. Rejected files stay visible when you explicitly process the valid files.
What happens when the requested size cannot be achieved?
The result is labeled Requirements not met, with its actual size and the conflicting constraints. For example, 22,100 bytes fails a 20,000-byte maximum. Retry with a lower minimum quality, another format, or explicit permission to reduce dimensions. Exact dimensions stay fixed. An unmet output can be downloaded, but must not be treated as meeting your upload rule.
Can I compress or convert HEIC and animated images?
Supported HEIC/HEIF inputs decode locally using a decoder loaded on demand. Choose JPEG, PNG or WebP explicitly: HEIC output is unavailable. Unusual variants, HDR profiles or damaged files may fail. Animated PNG/WebP and HEIF sequences export one still image, not an animation. GIF input is unsupported.