Image Compressor & Converter

These four cover the vast majority of bitmap images on the modern web: JPEG is the de-facto standard for photos, PNG handles lossless and transparency, WebP is the efficient modern format supported by every current browser, and AVIF is the next generation (typically 20-50% smaller than WebP). BMP and TIFF are uncompressed and not suited for the web; HEIC is Apple-specific with limited browser support; GIF's animation is outside the scope of "static compression". Focusing on these four covers 95%+ of everyday use cases.

PNG is lossless — it cannot throw away any pixel data, only reorganize it using ZIP-like algorithms. For photos (where neighbouring pixels are noisy and different), lossless algorithms have almost nothing to work with, which is why savings are often just 5-15%. To shrink a photo meaningfully you have two options: accept lossy encoding and switch to JPEG or WebP, or, if you truly need lossless, switch to lossless WebP or AVIF, which are usually 30-50% smaller than PNG.

Every image contains "information entropy" — essentially the colour data of its pixels. Lossy encoders (JPEG / WebP / AVIF) break through that limit by discarding details the human eye is less sensitive to: the lower the quality setting, the more is thrown away and the smaller the file, but the worse it looks. Lossless encoders can't drop any detail and can only find redundancy in existing data, so they hit a wall quickly. In other words: the compression ceiling is set by image quality, not by the tool.

WebP has the best compatibility (every browser since 2014) and encodes fast — a safe default. AVIF typically saves another 20-40% but is much slower to encode (a 4000×3000 photo can take 10-30 seconds) and very old browsers don't support it. For mainstream websites and CMS bulk processing, WebP is the safer pick; for static sites, technical blogs or situations where file size really matters (e.g. an e-commerce catalogue with hundreds of product shots), AVIF is worth the wait.

Two different things can be lost. Lossy formats (JPEG, lossy WebP, lossy AVIF) drop pixel data — how much is controlled by the quality setting; 75-90 is the usual "you can't really tell" range. Lossless formats (PNG, lossless WebP, lossless AVIF) keep every pixel but strip all metadata (EXIF, camera model, GPS location, capture time). That's actually a privacy bonus: cleaning that information before sharing is safer.

It mostly comes down to three things: output format, image size and the queue. AVIF is the slowest to encode — a 4000×3000 photo can take 10-30 seconds, in exchange for a much smaller file; more pixels mean more time, so a 6000×4000 photo takes far longer than a screenshot; and images are processed one after another in the background, so each task waits for the previous one to finish. For faster results, switch to JPEG or WebP output, or cap the maximum width/height first.

Three common causes: the source was already efficiently compressed (e.g. it was already WebP or AVIF), so re-encoding it in the same format just compresses an already-compressed result and often grows it; the image is very small (a few dozen KB — icons, thumbnails), where the encoder's header overhead can outweigh the pixel savings; or you converted lossless PNG to lossy JPEG at too high a quality setting, which preserves more detail. This tool detects that case automatically, keeps the original file and shows "Original kept" in the result row.

No. Images are decoded, resized and re-encoded in your browser with the Canvas API. The file contents never leave your device.

Any common browser-decodable image works as input. JPEG, PNG, WebP and AVIF output is produced by the bundled WASM encoders instead of the browser itself, so WebP and AVIF export work in every modern browser.

Not in the output. When the format stays the same and dimensions are unchanged, the original file is kept automatically if re-encoding does not make it smaller, marked as “Kept original”. Explicit format conversion and resizing always honor your chosen output (e.g. PNG to JPEG for compatibility may change the size either way).

No. Canvas re-encoding removes EXIF and other metadata, while applying the image orientation correctly. This also reduces file size and avoids exposing location or device details. Animated GIF files are processed as a static first frame.

PNG is lossless and is not ideal for compressing photos. For photos, screenshots and illustrations, JPEG or WebP usually produce smaller files. Use PNG when you need transparency or lossless pixels.

No. Compression reduces file size while preserving acceptable quality; it cannot restore lost detail. Keep the original and export a compressed copy for the web, social media or sharing.

Saving many files individually can trigger the browser’s multiple-download confirmation. A ZIP downloads one file and is more convenient for large batches.

Once a file finishes, a download button appears on the right side of its result row — click it to save that one. You can also use the toolbar’s "Save individually" or "Download ZIP" for bulk downloads. If your browser asks whether to allow multiple file downloads, choose Allow; ZIP mode avoids that prompt entirely.