Image Compressor & Converter

Drop images to batch-compress, convert to WebP/JPG/PNG or resize — all in your browser, nothing uploaded.

Drop images here or click to choose JPG, PNG, WebP, AVIF, GIF (first frame), HEIC (Safari) · multiple files · Ctrl+V to paste

    No images yet. They are compressed automatically with the settings shown; change any setting and results update.

    Original
    Original
    Compressed
    Compressed

    This browser cannot display the original (e.g. HEIC), so only the result is shown.

    Download this image

    Privacy: images are decoded and compressed only inside this browser (Web Worker / Canvas). 17NAS servers never receive your images or file names, and results are discarded when you close the page.

    Quick answer

    Drop images here (several at once, or paste a screenshot), pick an output format and quality, and they are compressed right away in your browser, with the original size, new size and percentage saved shown for each file. Photos converted to WebP at quality 75–80 typically shrink by 60–80% with no visible difference, and PNG screenshots reduced to 256 colours often shrink by around half. You can also cap the width/height, hit a target size in KB and strip EXIF and GPS location, then download files one by one or as a ZIP. Your images never leave your device.

    How to use (4 steps)

    No sign-up or install. Large batches are processed in the background without freezing the page.

    1. Image compressor drop zone with several photos added and compression in progress
      Step 1

      Add images

      Drag images into the dashed box, tap “Choose images” to pick several, or paste a screenshot with Ctrl+V. Compression starts right away.

    2. Output settings panel with format buttons, quality slider, resize and target size options
      Step 2

      Pick format, quality and size

      In “Output settings” choose Same, JPG, PNG or WebP and drag the quality slider; optionally cap width/height or enter a target KB. Results update automatically.

    3. Before/after comparison window with a slider between original and compressed image
      Step 3

      Compare before and after

      Tap “Compare” on a row and drag the divider or switch to side-by-side to check quality. Every row shows the size change and percentage saved.

    4. Result list with totals and the Download all (ZIP) button
      Step 4

      Download

      Use the download button on a row to save one file, or “Download all (ZIP)” for everything. The summary shows the total saved.

    Start compressing

    Key facts at a glance

    Price
    Free, no sign-up, no watermark
    Input formats
    JPG, PNG, WebP, AVIF, GIF (first frame), BMP; HEIC in Safari
    Output formats
    JPG, PNG (with colour reduction), WebP; AVIF depends on browser
    Batch
    Up to 300 images, single or ZIP download
    Size controls
    Max width/height or percentage; target size in KB
    Metadata
    EXIF and GPS removed by default; EXIF optional for JPG
    Privacy
    Processed locally, nothing uploaded
    Browsers
    Latest Chrome, Edge, Firefox, Safari; works on phones
    Offline
    Keeps working offline once the page has loaded
    Last updated

    Which image format should I use?

    The same picture can differ several-fold in size between formats. Choosing the right format beats simply lowering quality.

    Format Best for Transparency Notes
    JPG Photos where maximum compatibility matters No Opens everywhere; transparent areas are filled with a background colour
    PNG Screenshots, icons, text and line art Yes Lossless but large; 256-colour reduction often halves it
    WebP Websites, chat apps and most everyday sharing Yes About 25–35% smaller than JPG at similar quality; supported by all major browsers
    AVIF Web images where the smallest size matters Yes Best compression, but slow to encode and some older devices cannot open it
    GIF Simple animations (this tool uses the first frame) Yes Max 256 colours; use PNG or WebP for still images
    HEIC iPhone’s default photo format Yes Small but poorly supported; convert to JPG or WebP before sharing

    How it works and tips

    JPG, WebP and AVIF are lossy: lowering “quality” discards detail the eye barely notices in exchange for smaller files. This tool re-encodes images with the browser’s built-in encoders. Quality 75–82 looks identical for most photos; below 60, blocks start to appear in skies and gradients.

    PNG is lossless, so “quality” does not shrink it. “PNG colours” maps the image to a palette of 256 colours or fewer (median cut with optional Floyd–Steinberg dithering) and writes an indexed PNG that keeps transparency — the same idea as TinyPNG. UI screenshots and icons typically shrink by 40–70%.

    Dimensions often matter more than quality. Phone photos are commonly 4000×3000 pixels, while 1920 pixels wide is plenty for social media or a web page — about three quarters fewer pixels. For upload limits such as “max 200 KB”, tick “Compress to a target size”: the tool finds the highest quality that fits and steps the size down only if needed.

    Features and limitations

    What the tool can and cannot do, so you know before you start.

    Feature Status Notes
    Batch compression and ZIP Yes Up to 300 images, processed in a background Web Worker
    Lossy JPG / WebP Yes Quality 10–100; Safari 16 and older cannot export WebP
    PNG compression Yes Palette of 256/128/64/32 colours (optional dithering), transparency kept; lossless also available
    Target file size Yes Quality is searched automatically for JPG/WebP/AVIF, then size is reduced if needed
    Resize Yes Fit within max width/height or scale by %; never upscales
    AVIF output Partial Depends on the browser’s AVIF encoder; greyed out when unavailable
    HEIC / HEIF photos Partial Safari (iPhone/Mac) converts them to JPG; Chrome and others cannot decode HEIC yet
    Keep EXIF Partial JPG → JPG only; orientation is normalised so images are not rotated twice
    Animated GIF / APNG No Only the first frame is exported; animation is not kept
    SVG vector images No SVG is not processed — use an SVG optimiser

    FAQ

    Are my images uploaded to a server?

    No. Decoding, resizing, encoding and zipping all happen in your browser (Web Worker + Canvas). You will not see any image upload in the network panel, and the tool keeps working offline after the page loads.

    Will quality suffer? What quality should I use?

    Lossy formats drop a little detail, but photos at 75–82 usually look the same — check with the Compare slider. For text screenshots use PNG colour reduction or WebP 90+ to keep edges crisp.

    How do I compress an image to under 200 KB or 100 KB?

    Tick “Compress to a target size”, enter 200 (or 100) and choose JPG or WebP output. The tool binary-searches the highest quality that fits; if even the minimum quality is too big it reduces the dimensions step by step and says so in the list.

    JPG, PNG, WebP or AVIF — which should I choose?

    WebP for photos on websites or in chat; JPG when every device must open it; PNG (colour-reduced) or WebP for screenshots, icons and transparency; AVIF is smallest but needs browser export support. See the format table above.

    How do I compress a PNG? Why does lossless PNG barely shrink?

    PNG is already losslessly compressed, so re-saving rarely helps. Colour reduction is what works: the default 256 colours looks the same for most screenshots and icons and usually cuts 40–70%. Colour-rich photos are better converted to WebP or JPG.

    Can I convert iPhone HEIC photos to JPG?

    Yes, in Safari on iPhone, iPad or Mac — it converts HEIC to JPG (or WebP) directly. Chrome and Edge cannot decode HEIC yet and will show an error. You can also set iPhone Settings › Camera › Formats to “Most Compatible” to shoot JPG from now on.

    What does “remove EXIF” mean, and do I need it?

    EXIF is the shooting information embedded in photos — it can include GPS coordinates, phone model, time and even a thumbnail. Removing it before sharing publicly avoids leaking where you live and saves tens of KB. It is removed by default; to keep it (e.g. for photography), untick the option and output JPG.

    How many images at once? Does it work on phones?

    Up to 300 per batch. Computers process 2–3 in parallel; phones go one at a time to save memory, and very large images are scaled to the device limit (about 16 megapixels on iPhone). Save results one by one or as a ZIP.

    Why did some images get bigger?

    If the original is already heavily compressed (a low-quality JPG) or you convert a photo to PNG, the output can be larger. “Keep the original if the result is larger” (on by default) falls back to the original — with metadata stripped — when format and size are unchanged; when converting, lower the quality or use WebP.

    Is transparency kept? Why does JPG turn it white?

    PNG, WebP and AVIF keep transparency. JPG cannot store it, so transparent areas are filled with a background colour (white by default, changeable under “More options”). For small files with transparency use WebP or colour-reduced PNG.