Which tool for which job
Start from the task, not the format:
- A photo is too big for a form or an email: Resize image first, then Compress JPG.
- A screenshot, logo or diagram is too heavy: Compress PNG.
- An animated GIF is too heavy: Compress GIF.
- An iPhone photo will not open: HEIC to JPG.
- A picture saved from a website is WebP or AVIF: WebP to JPG, WebP to PNG or AVIF to JPG.
- Images for your own website: JPG to WebP for photos, PNG to WebP for graphics with transparency.
- Switching between the two classics: PNG to JPG for photos stored as PNG, JPG to PNG for a lossless editing copy.
- A vector logo is needed as a picture: SVG to PNG, or Favicon generator for the full set of site icons.
- Wrong shape or orientation: Crop image and Rotate image.
- A cut-out or a bigger version: Remove background and Upscale image.
- Text or a QR code inside a picture: Image to text and Read QR code.
- Privacy and credit: EXIF viewer shows what a photo reveals, Remove EXIF cleans it, Watermark image marks it as yours.
- Deciding between two settings: Compare images puts both versions under one slider.
The formats in plain numbers
JPG (1992) is built for photographs. It splits the picture into 8×8 pixel blocks and rounds away detail the eye is unlikely to notice. Quality 75 to 85 is the sweet spot: a 12 MP photo is around 3 MB at 85 and 15 to 25 MB stored as PNG. It has no transparency and loses detail with every save.
PNG (1996) is lossless and keeps an alpha channel. It is the right format for screenshots, logos, charts and anything with text, and the wrong one for photos. A 1920×1080 screenshot is about 8 MB of raw pixels and typically 1 to 3 MB as PNG; reducing it to a 256-colour palette often halves that again.
WebP is a delivery format. A photo is usually a quarter to a third smaller than the equivalent JPG, and unlike JPG it keeps transparency, so a 2 MB PNG product cut-out can land at 150 to 400 KB. Every current browser shows it, but keep originals in JPG or PNG. Sides are limited to 16383 px.
AVIF stores a still image as one AV1 video frame: a photo that needs 400 KB as JPG often fits in 100 to 150 KB. Outside browsers, support is still patchy.
HEIC is what iPhones have saved since iOS 11 in 2017, about half the size of JPG at the same detail. Windows, many forms and older Android phones do not open it.
GIF (1987) is limited to 256 colours and stores every frame almost in full, so a short clip can weigh 15 MB. SVG describes shapes as text and renders sharply at any width.
A quick rule: taken with a camera, use JPG; drawn on a computer, keep PNG; published on a site, convert a copy to WebP.
What happens to your files
Every image tool runs in your browser. There is no upload and no server option in this category, so there is no daily limit either: the only constraints are the per-file sizes and your device's memory. Most tools accept files up to 50 MB; Remove background, Upscale image, Image to text and Read QR code take up to 30 MB, SVG and favicon sources up to 20 MB, and GIFs up to 100 MB.
The three tools that use trained models download them once and keep them in the browser cache: about 45 MB for background removal, about 5 MB for the ×4 upscaler, and the Tesseract language data for text recognition. Later runs start immediately. Upscaling is capped at 16 megapixels of output, which means sources up to about 1 MP for ×4 and about 4 MP for ×2.
Tools that redraw the picture, such as resize, crop, rotate, watermark and the converters, write a fresh file without the original EXIF block. JPG and WebP output from resize, crop, rotate and watermark is saved at quality 92. Remove EXIF works differently: it copies the image data byte for byte and only drops the metadata sections, so the pixels stay identical.
Workflows that chain well
- Phone photo for an upload form: convert with HEIC to JPG, resize to 2048 px on the long side, then compress at 80. A 12 MP photo usually ends well under 1 MB.
- Product shot for a shop: crop close to the item, remove the background, resize to display size, then PNG to WebP to keep transparency or PNG to JPG with a white background for marketplaces.
- Logo to site icons: square it with Crop image, upscale a small raster version if needed, then run the Favicon generator.
When the result is not what you expected
- The file barely shrank or the row says the original was kept. It was already compressed. Re-encoding would make it larger, so the original is returned unchanged.
- The JPG is bigger than the WebP, AVIF or HEIC it came from. Expected: those formats are more efficient. Lower the quality or resize if the size matters.
- Transparent areas turned white or black. JPG has no alpha channel. Use PNG or WebP output, or pick a background colour that matches the destination.
- A photo lies on its side after cleaning metadata. The orientation tag was part of the EXIF block. Fix it with Rotate image.
- A HEIC file is rejected by crop, compare or remove EXIF. Only the HEIC converter and the EXIF viewer read it directly; convert to JPG first.
- The tab reloads during a big batch. 50-megapixel photos need hundreds of megabytes each to decode. Process fewer files at a time or use a desktop browser.