Lumagely
English

Optimize images — compress, convert & resize. Total privacy.

Compress, convert, resize, crop, rotate and watermark as many images as you like — even down to a target file size. Free, no sign-up, no uploads. Everything runs privately in your browser.

  • No uploads — 100% on-device
  • Fast in-browser processing · WASM codecs
  • Unlimited files · up to 256MB each

Drop images here

or Browse files

Tip: paste images directly with Ctrl+V

HEIC · PNG · JPEG · WebP · AVIF · GIF · SVG

How it works

Three steps, zero uploads — everything happens in your browser.

  1. Add your images

    Drag & drop, paste with Ctrl+V, or browse. HEIC (iPhone photos), PNG, JPEG, WebP, AVIF, GIF and SVG are all supported.

  2. Choose your settings

    Pick a compression mode (or a target file size), output format, and optional resize, crop, rotate or watermark. Changes re-apply to every image automatically.

  3. Download

    Save each optimized image, or grab the whole batch as a ZIP. Nothing is ever sent to a server.

Everything you can do

A complete image toolkit — compress, convert, resize, crop, rotate and watermark — all running privately in your browser.

  • Smart compression

    Shrink PNG, JPEG, WebP and AVIF with WebAssembly codecs — Smart Auto, lossy, near-lossless or fully lossless.

  • Target file size

    Set a limit in KB and Lumagely finds the best quality that fits — ideal for upload caps and email attachments.

  • Convert & HEIC to JPG

    Convert between PNG, JPEG, WebP and AVIF, turn iPhone HEIC photos into JPG, and modernize old GIFs.

  • Resize, crop & rotate

    Resize by pixels or percentage, crop to any aspect ratio, and rotate or flip — across the whole batch.

  • Batch watermark

    Stamp a text or logo watermark onto every image, with full control over position, size, opacity and margin.

  • Private & offline

    Everything runs on your device in Web Workers — no uploads, no sign-up, and it keeps working offline.

Supported formats

Compress, convert and optimize the formats the modern web runs on.

  • HEIC

    Convert iPhone HEIC photos to JPG, PNG, WebP or AVIF.

  • PNG

    Lossless compression with OxiPNG.

  • JPEG

    High-quality photos with MozJPEG.

  • WebP

    Smaller photos & graphics, lossy or lossless.

  • AVIF

    Next-gen format with the best compression for photos.

  • SVG

    Minify vectors, or trace raster images into SVG.

  • GIF

    Convert GIFs to modern, smaller formats.

Resize images for social media

Export pixel-perfect sizes for every major platform — crop to fill or pad to fit, then save as JPEG, PNG or WebP. All on your device.

  • Instagram

    4 sizes

    Square and portrait feed posts, full-screen Stories and profile pictures.

    • Square post1080×1080
    • Portrait post1080×1350
    • Story1080×1920
    • Profile picture320×320

  • Threads

    3 sizes

    Square and portrait posts plus profile photos for Threads.

    • Square post1080×1080
    • Portrait post1080×1350
    • Profile picture320×320

  • Facebook

    5 sizes

    Link previews, square posts, cover photos, Stories and profile pictures.

    • Link post1200×630
    • Square post1080×1080
    • Cover photo820×312
    • Story1080×1920
    • Profile picture320×320

  • Twitter / X

    3 sizes

    In-stream post images, header banners and profile pictures for X.

    • Post1600×900
    • Header1500×500
    • Profile picture400×400

  • LinkedIn

    3 sizes

    Profile cover banners, shared post images and profile photos.

    • Cover banner1584×396
    • Post1200×627
    • Profile picture400×400

  • YouTube

    2 sizes

    Video thumbnails and channel avatars at the recommended resolution.

    • Thumbnail1280×720
    • Channel avatar800×800

  • Pinterest

    2 sizes

    Standard vertical Pins and profile pictures, sized to spec.

    • Standard Pin1000×1500
    • Profile picture280×280

Why Lumagely?

100% private

Your images are processed on your device and never uploaded to any server.

Fast & modern

WebAssembly codecs (MozJPEG, OxiPNG, libwebp, libavif) run at near-native speed in your browser.

Free & unlimited

No sign-up, no forced watermarks, no limits — optimize as many images as you like.

Browser-based vs. upload-based

Typical upload tools

  • Images are uploaded to a server
  • Sign-up or usage limits are common
  • Often split across separate tools
  • Privacy depends on the provider

Lumagely

  • Images stay on your device
  • No sign-up — unlimited files
  • Compress, convert, resize and social export in one place
  • Private by design — nothing leaves your browser

Frequently asked questions

Are my images uploaded to a server?

No. Lumagely processes everything on your device using WebAssembly codecs running in your browser. Your images never leave your computer or phone.

Is Lumagely free to use?

Yes. Lumagely is completely free with no sign-up, no watermarks and no limit on how many images you optimize.

Which image formats are supported?

You can compress and convert PNG, JPEG, WebP and AVIF, convert HEIC/HEIF (iPhone photos) and GIFs, and optimize SVG files. You can also vectorize raster images into SVG.

How do I convert PNG to WebP or JPG to AVIF?

Drop your images in, choose the output format (WebP, AVIF, JPEG or PNG) and Lumagely re-encodes them instantly in your browser. Then download individually or as a ZIP.

Can I convert an image to SVG?

Yes. Choose the SVG output format to vectorize a raster image into vector shapes. It works best for logos, icons and flat graphics rather than photos.

Will compressing reduce image quality?

Only if you want it to. Smart Auto and Near-lossless keep images visually identical while shrinking the file. Lossless mode preserves every pixel, and Lossy lets you pick the exact quality.

Can I resize and batch-process images?

Yes. Resize by pixel dimensions or percentage across the whole batch, then download every optimized image at once as a ZIP archive.

Does Lumagely work offline?

After the first load, the app runs entirely in your browser without contacting any server, so image processing keeps working with no connection.

Can I resize images for Instagram, Facebook and other social media?

Yes. Social export creates pixel-perfect sizes for Instagram, Threads, Facebook, Twitter/X, LinkedIn, YouTube and Pinterest — including posts, stories, covers, headers, thumbnails and profile pictures. Choose crop or pad with a background color, pick JPEG, PNG or WebP, optionally stamp your text or logo watermark, then export one size or several at once as a ZIP — all on your device.

How do I convert HEIC (iPhone photos) to JPG?

Drop your .heic or .heif files in and pick JPG as the output format — Lumagely decodes the iPhone HEIC and re-encodes it to JPEG (or PNG, WebP or AVIF) right in your browser, keeping the correct orientation. The photos are never uploaded, and you can convert a whole batch and download it as a ZIP.

Can I compress an image to a specific file size?

Yes. Choose the Target file size mode and set a limit in KB — Lumagely automatically finds the highest JPEG, WebP or AVIF quality that fits under your target. If even the lowest quality is still too large, reduce the dimensions with the resize option as well.

Can I rotate, flip or crop images?

Yes. Open the crop tool on any image to crop it to any aspect ratio, rotate it left or right, or flip it horizontally or vertically. The changes are baked into the exported file, and you can apply a single crop ratio across the whole batch too.

Can I add a watermark to my images?

Yes. Add a text or logo watermark to your whole batch and control its position, size, opacity and margin. Your logo stays on your device — like every image, it is never uploaded to a server.

Popular tools

One-tap tools for the most common image jobs — all free, all in your browser.