Photo tools are the category where uploading matters most and is questioned least. A holiday snapshot is harmless; a photo of a document, a product shot before launch, or a picture taken at home with its GPS block intact is not. These tools never send the file anywhere, which also means there is no upload limit and no waiting in a queue.
Between them they cover the jobs that come up again and again: make it smaller, change the format, remove what is hidden inside it. Each one processes as many files as your browser can hold in memory.
Questions
Can I process several images at once?
Yes. Every image tool here takes up to 30 files per batch and applies the same settings to all of them.
What happens to image quality?
Resizing and converting re-encode the image, so JPEG and WebP output depends on the quality setting. PNG output is lossless. The resizer never enlarges an image, because that adds pixels but no detail.
Do these work with HEIC photos from an iPhone?
No. Browsers cannot decode HEIC. Set your iPhone to Most Compatible under Settings, Camera, Formats and it will produce JPEG instead.