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  1. Home
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  3. Image Compressor
Image

Image Compressor

Compress JPG, PNG, WebP, and GIF images right in your browser — batch upload multiple files, adjust quality with a slider, and see before/after size savings instantly. Nothing is ever uploaded to a server.

Try:

Drag and drop images here, or click below to browse. JPG, PNG, WebP, and GIF supported.

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How To Use

  1. 1.Drag and drop one or more images onto the upload area, or click it to browse your files — JPG, PNG, WebP, and GIF are all supported, and you can select several at once.
  2. 2.Adjust the Quality slider (1-100) to control the compression level — lower values produce smaller files with more visible quality loss, higher values keep more detail at a larger size.
  3. 3.Each image compresses automatically in the background; watch the before/after preview and the size comparison update for every file in your batch.
  4. 4.Compare the original size, compressed size, and savings percentage shown on each image card to see exactly how much space you saved.
  5. 5.Download any compressed image individually, or copy it straight to your clipboard to paste elsewhere.
  6. 6.Remove an image from the batch with its X button, or use Reset to clear everything and start over.

Examples

Gradient sample image
A generated gradient image with smooth color transitions — a good stand-in for compressing a photo.
Noise pattern sample image
A generated high-entropy noise image — a worst-case pattern for showing how much harder noisy images are to compress.

About Image Compressor

Why Compress Images?

Images are typically the single largest contributor to a web page's total download size, often outweighing all of a page's HTML, CSS, and JavaScript combined, which makes image compression one of the highest-impact web performance optimizations available. A smaller image downloads faster, especially over slower mobile connections where every kilobyte adds measurable delay, and it reduces bandwidth costs for anyone hosting or serving that image at scale — whether that's a personal blog, an e-commerce product catalog, or an app's user-uploaded photo gallery.

Beyond web performance, compression matters anywhere storage or transfer size is a practical constraint: email attachment limits, messaging app upload caps, cloud storage quotas, or simply wanting a folder of vacation photos to take up less space on a phone. A well-compressed image at a sensible quality setting is visually indistinguishable from the original in the vast majority of everyday viewing contexts, while taking a fraction of the space — which is exactly the tradeoff a quality slider is designed to let you control directly, rather than accepting a single fixed compression level.

Lossy vs Lossless Compression

JPEG and WebP (in its lossy mode) use lossy compression, meaning some original image information is permanently discarded during encoding in exchange for a substantially smaller file — the encoder is specifically designed to discard the visual information human perception is least sensitive to first (subtle color gradients and high-frequency detail) while preserving the information we notice most (overall shapes, edges, and brightness), which is why a well-chosen lossy quality setting can look nearly identical to the original despite containing meaningfully less data. PNG uses lossless compression instead, meaning the exact original pixel values are always perfectly recoverable — no visual information is ever discarded, which is essential for screenshots, diagrams, and graphics with sharp edges or text, but which also means PNG can't shrink nearly as dramatically as a lossy format for photographic content.

WebP is notable for supporting both modes in a single format — lossy WebP typically produces smaller files than equivalent-quality JPEG, and lossless WebP typically produces smaller files than equivalent PNG, which is why it's become a popular modern choice for web images where browser support allows. Choosing the right format for the content matters as much as choosing the right quality setting: a photograph almost always compresses better as JPEG or WebP, while a screenshot or logo with flat colors and sharp edges almost always compresses better, and looks better, as PNG or lossless WebP.

How Browser-Based Image Compression Works

This tool works by drawing your uploaded image onto an in-memory HTML canvas element, then asking the browser's own built-in image encoder to re-export that canvas as a new file at your chosen quality — the same underlying encoding engine your browser already uses whenever it saves or exports any image, just invoked programmatically rather than through a 'save image' menu. Because this all happens through standard, well-supported browser APIs (Canvas and the File/Blob APIs), no server round-trip or third-party image-processing service is needed at any point in the process.

To keep the page responsive while compressing larger images or batches, the actual encoding work runs inside a Web Worker — a separate background thread the browser provides specifically for computationally heavy tasks — so compressing a large batch of photos doesn't freeze the rest of the page or block you from continuing to interact with the upload area while earlier images finish processing.

Image Compression Best Practices

Match the format to the content: use JPEG or WebP for photographs and complex, gradient-rich images where some quality loss is imperceptible at normal viewing sizes, and use PNG (or lossless WebP) for screenshots, logos, icons, and anything with sharp edges, flat colors, or transparency, where lossy artifacts would be immediately visible as blockiness around edges or text. Compress images at the resolution they'll actually be displayed at — compressing a 4000-pixel-wide photo down in file size while still keeping it 4000 pixels wide wastes the compression's potential if it will only ever be shown at 800 pixels wide on a page; resizing to the actual display size first, then compressing, produces dramatically better results than compression alone.

Always keep an original, uncompressed (or minimally compressed) master copy of any image you care about, since repeatedly re-compressing an already-lossy JPEG or WebP file (open, edit, re-save, repeat) compounds quality loss with each pass — a problem sometimes called 'generation loss.' Compress from the original source each time you need a new output, rather than compressing an already-compressed file further. Finally, use the before/after preview and the exact savings percentage this tool shows you rather than guessing at a quality number — the right setting genuinely varies by image content, and a value that looks great on one photo might show visible artifacts on another with more fine detail or sharper edges.

FAQs

No. Every part of this tool — decoding your image, applying compression, and generating the before/after preview — runs entirely inside your browser using the Canvas API and a dedicated web worker, with no server-side component involved in processing your files at any point. This means you can safely compress personal photos, unreleased product images, or confidential screenshots without any of the image data ever leaving your device or being transmitted anywhere. You can confirm this yourself by opening your browser's developer tools and watching the network tab while you compress an image — you won't see any outgoing requests carrying image data. Even if your internet connection drops after the page has finished loading, compression keeps working exactly the same, since it has no dependency on a live server connection to function.

For lossy formats — JPEG, WebP, and (for compression purposes) GIF, which is re-encoded through the same pipeline — the quality value controls how aggressively the compressor discards fine visual detail that's less perceptible to the human eye, similar to the quality slider you'd see when exporting from Photoshop or an online 'save for web' tool. A higher value (closer to 100) preserves more detail and produces a larger file; a lower value (closer to 1) discards more detail for a smaller file, and at very low values you'll start to see visible compression artifacts like blockiness or color banding, especially around sharp edges. The slider only affects lossy compression strength — it does not resize, crop, or change the dimensions of your image, so you get the exact same width and height back, just re-encoded at your chosen quality.

PNG is a lossless format by design — the browser's underlying image encoder always reconstructs a PNG's pixels exactly, with no quality setting that trades detail for size the way JPEG's does, so PNG files often shrink only modestly (or not at all) when run through a quality-based compressor like this one. This is expected, correct behavior, not a bug: PNG is the right choice specifically when you need pixel-perfect, lossless output (screenshots, graphics with sharp text or transparency, logos), and JPEG or WebP are the right choice when you can accept some quality loss in exchange for a meaningfully smaller file. If a PNG isn't shrinking as much as you'd like, converting it to WebP or JPEG (where visual quality allows) will typically produce far bigger size reductions than any amount of PNG-specific compression can.

No — because compression works by drawing your image onto an HTML canvas and re-encoding it, an animated GIF's multiple frames get flattened down to a single static frame in the output, the same limitation every canvas-based image tool shares. If preserving animation is essential, don't run an animated GIF through this tool; if you specifically need a smaller animated GIF, you'll need a dedicated GIF-frame-aware compressor rather than a general quality-based image compressor like this one. Static (non-animated) GIFs compress normally with no such limitation, since there's only ever one frame to begin with.

For photographs intended for web use, 70-85 is a well-established sweet spot that's very difficult to distinguish from the original at normal viewing sizes while still cutting file size substantially — this is roughly the range most professional 'save for web' workflows default to. For images where fine detail genuinely matters (product photography someone might zoom into, printed material, professional portfolios), stay higher, in the 85-95 range. For thumbnails, background images, or anywhere an image will be displayed small or isn't the primary visual focus, you can often go as low as 40-60 without a viewer noticing any difference, capturing much bigger file size savings. Since this tool shows you a live before/after preview and exact size numbers, the most reliable approach is simply dragging the slider and watching both the preview and the savings percentage until you find the point where quality loss becomes noticeable — then back off slightly from there.

Yes — this tool is built for batch processing from the ground up. Drop or select as many images as you like in one go, and each one compresses independently using the same quality setting, with its own before/after preview, size comparison, and download button. Changing the quality slider re-compresses every image currently in your batch using the new setting, so you can quickly compare how the same quality value affects a whole set of different images side by side, rather than having to re-upload and re-adjust one file at a time.

No — this tool is configured to always preserve your image's original width and height exactly; only the encoding quality changes, never the resolution. This is a deliberate choice: resizing and quality compression solve different problems (resizing reduces pixel count, quality compression reduces how efficiently those same pixels are encoded), and mixing the two into a single slider makes it harder to reason about exactly what a given setting will do to your file. If you also need to resize an image, use a dedicated image resizer tool either before or after compressing.

There's no hard-coded limit on how many images you can add to a batch, and individual files up to roughly 25 MB compress reliably in most browsers — well beyond the size of a typical photo, even from a modern smartphone camera. Because everything runs in your browser's memory rather than being streamed to a server, extremely large files or very large batches (dozens of high-resolution images at once) can use a meaningful amount of RAM and CPU while compressing; if you notice your browser tab becoming sluggish with a very large batch, compressing in smaller groups will generally feel snappier.

This can happen when you compress an image that's already been efficiently encoded — a JPEG previously saved at a similarly low quality, or a PNG that was already well-optimized — since re-encoding adds a small amount of its own overhead, and at a high quality setting that overhead can occasionally exceed whatever minor savings the new encoding pass finds. It's also common with PNGs specifically, since PNG's lossless encoding has less room to shrink to begin with (see the PNG question above). If you see a compressed file that's larger than the original, try lowering the quality slider further, or recognize that the source file may simply already be close to optimally compressed for its format.

Nothing is retained anywhere — since compression happens entirely in your browser's memory using temporary object URLs for the before/after previews, closing the tab, refreshing the page, or navigating away immediately and permanently discards every image you uploaded and every compressed result, with nothing persisted to a server, a database, or even browser storage like localStorage. This is the same reason nothing you compress here can be recovered later from this tool if you forget to download it first — make sure to download (or copy) any result you want to keep before leaving the page.

Related Tools

Image Compressor reduces file size while keeping images in their original format and dimensions. These related image tools cover other common parts of an image-optimization workflow.

WebP Converter
ImageConvert JPG or PNG images to the more efficient WebP format for even bigger size savings.
Image Resizer
ImageResize an image's dimensions before compressing it for the biggest possible file size reduction.
PNG to JPG
ImageConvert lossless PNGs to JPEG when photographic content would compress far better as a lossy format.
Image to Base64
ImageEncode a compressed image as a Base64 string for embedding directly in CSS, HTML, or JSON.