RunToolRunBatch Image Converter
Convert multiple images in batch.
How to Batch Convert Images
Select images in any format
Drop a mixed batch of PNG, JPG and WebP files — the converter handles them together.
Choose the output format
Pick PNG, JPG or WebP as the target. Conversion runs instantly in your browser.
Download all results
Save converted images individually or grab everything as a single ZIP.
Choosing a format is choosing what to give up
Every image format trades three things against each other: file size, exactness and features. PNG keeps every pixel and supports transparency but is large for photographs. JPEG is small for photographs but discards detail and has no transparency. WebP is smaller than both and keeps transparency, at the cost of some software still refusing to open it.
There is no best format, only a best match for a destination. A photograph for an email attachment, a logo for a website and a screenshot for documentation each have a different correct answer, and picking by habit rather than by destination is what produces bloated pages and fuzzy logos.
A rule that covers most cases
If the image is a photograph and it is going on the web, use WebP; if it must open anywhere without question, use JPEG. If it contains transparency, use PNG or WebP and nothing else. If it is flat graphics, text or a screenshot, avoid JPEG entirely — hard edges are precisely what its compression handles worst.
Applying that consistently matters more than tuning quality settings. Moving a screenshot from JPEG to PNG improves it more than any JPEG quality value can, and moving a photograph from PNG to WebP saves more than any amount of PNG optimisation.
Generation loss and conversion direction
Converting between lossy formats — JPEG to WebP, WebP to JPEG — decodes and re-encodes, adding a generation of loss each time. Converting from a lossless source to anything is a single generation. Converting a lossy file to a lossless one preserves the damage already done while multiplying the file size.
The practical discipline is to keep one master in the highest-quality form you have and generate every other version from it. Converting a converted file, repeatedly, is how images quietly degrade over months without anyone noticing a single moment where it happened. Note also that converting to JPEG fills transparency with white, permanently.
Batch conversion in the browser
Conversion uses the browser's own image encoders on your device, so nothing is uploaded and there is no per-file size limit imposed by a server. For product photographs, client work and screenshots of internal systems, that is the difference between a private operation and handing a folder of images to an unknown service.
The constraint is memory. Each image is decoded to a full-resolution bitmap before being re-encoded, so a large batch of high-resolution files is demanding — converting in groups is more reliable than queueing everything at once, particularly on a phone or tablet.