Image Compressor

Start with the job, then choose settings

1. Keep the source file separately. Add still JPG, PNG or WebP images by selection, drag and drop, or clipboard paste.
2. For a constrained upload, read its current format, byte and dimension rules. Enter those in Upload requirements checker; the checker reports compliance but does not set compression controls.
3. Choose output format, maximum dimensions and, if needed, a size target. Start with one representative image before running a large batch.
4. Compress, compare and inspect the actual output. Download a file and check it in the destination before treating the whole batch as ready.

Individual settings override batch settings for that image. Loading a saved preset does not remove individual overrides or regenerate existing downloads. Recompress after changing settings so the file reflects your current choices.

Choose a format for the image and destination

• JPG is a practical candidate for opaque photos when the destination accepts it. It is lossy and replaces transparency with a white background here.
• WebP can combine lossy picture compression with transparency. The format supports more modes than this interface exposes; the quality control here does not provide a lossless WebP switch.
• PNG offers a rendered-pixel lossless option and palette reduction. Palette reduction is lossy and can alter gradients, brand colours and soft edges.

Auto selects JPG for opaque images and WebP for detected transparency when encoding is supported, with a PNG fallback. Browser display support is different from canvas encoding support. Test the actual output instead of assuming a browser name guarantees a format.

Read targets and upload checks separately

A target of 100 KB means a maximum of 100,000 bytes in this tool. For JPG and WebP, the algorithm searches tested quality settings up to your chosen maximum. Optional resizing can reduce dimensions further. PNG uses its selected compression mode rather than the JPG/WebP quality slider. A target may remain unmet.

The upload checker evaluates only entered format, size, dimensions and supported exact aspect ratio. A pass does not check the subject, legibility, document authenticity, colour requirements or every receiving-site rule. If a source is too small or has the wrong shape, the tool cannot enlarge or crop it to force a pass.

Find upload fixes prepares alternatives from the original. Compare them before applying one; the current result remains available until replaced. A passing candidate can still be unsuitable if text is unreadable or the destination has additional rules.

Check detail without mistaking zoom for a quality score

At 100% zoom, one output pixel occupies one CSS pixel. The original is aligned to the output dimensions, so the slider compares encoding at that size; it does not demonstrate that downscaling preserved all source detail. Inspect small text, faces, fine patterns and transparent edges at the intended viewing size as well.

A quality value of 80% is an encoder setting, not a statement that 80% of quality or bytes will remain. Browsers and formats can produce different results. When the same-format output would be no smaller and dimensions are unchanged, the tool can retain the original instead. Requested conversions or resizing can produce a larger file.

Storage, privacy and practical limits

Selected image contents are processed locally by this tool. The website still loads resources and may use shared services, so local processing is not a claim that the whole site makes no network requests or collects no website data. Saved presets store settings and rules in this browser’s local storage, not image contents; they are not synced and can disappear when site data is cleared.

The batch limit is 20 images. Each input can be up to 25 MiB (26,214,400 bytes, about 26.2 decimal MB), with at most 40 million decoded pixels and no side over 16,000 pixels. These limits do not guarantee enough device memory. PNG optimisation above 16 million output pixels uses a browser lossless fallback; palette reduction requires a smaller output.

ZIP download groups successful results; it does not establish that every target or upload rule passed, and it does not provide another image-quality improvement. Check each status. Animated PNG and WebP are rejected; GIF, SVG, HEIC and AVIF are not accepted inputs. Metadata can remain when an original is retained, so this is not a certified metadata-removal workflow.

Related image tasks

• Compress Image to 100KB
• Compress PNG
• PNG to WebP
• WebP to JPG or PNG