Convert PNG to JPG without installing software
Most of the results you get searching for this are sites that ask you to upload your photos to their server. It works, but it means handing your images to a company you do not know, waiting while it processes them, and downloading them back. There are two ways to avoid that.
Why convert, and what you lose
Before converting it is worth knowing what you are changing, because you cannot undo it:
- PNG compresses losslessly and supports transparency. It is heavy for photographs and light for screenshots, logos and flat-colour artwork.
- JPG compresses lossily and has no transparency. For photographs it is five to ten times lighter than a PNG of equivalent quality. What is lost does not come back.
- WebP does both: it compresses better than JPG at the same quality and supports transparency. Every current browser understands it, though some older desktop programs still do not.
What happens to transparency: convert a transparent PNG to JPG and the transparent areas get filled in, usually with white. If that logo was going to sit on a coloured background, it now carries a white box. In that case WebP is the right conversion, not JPG.
Method 1: Paint, for a single image
It ships with Windows and works if you have one image, not forty:
- Open the image with Paint.
- File → Save as → JPEG.
- Pick the folder and save.
The problem: one image at a time, no control over the compression quality, and no way to resize in the same step. For a whole batch it is unworkable.
Method 2: batch conversion inside your own browser
Modern browsers can decode and re-encode images on their own. That means a web page can convert your photos using your machine's processor, without sending anything to a server.
That is what Tanda does. You open the folder, pick the output format and apply. Because the conversion happens locally:
- Your photos are not transmitted anywhere.
- There is no size limit imposed by a server.
- It works with the wifi switched off.
- A batch of two hundred images takes seconds, not minutes of uploading.
The two settings that matter
Quality. Between 80 and 85 is the point where the file shrinks enormously and the difference is invisible. Below 70 you start seeing blotches in skies and areas of flat colour. Above 95 the file grows a lot for no visible gain.
Max width. A modern phone photo is 4000 pixels wide. For the web or an email that is overkill: 1920 covers a full screen, and 1200 is plenty for an image inside an article. Resizing before compressing cuts the weight more than any quality setting will.
Rename and convert in one pass
If you are converting a batch, it is usually because it is going somewhere: a website, a client, an email. And then the names matter too. Doing both at once makes sense: one rule that cleans up the names and adds a prefix, plus conversion to WebP with a max width of 1920. One step instead of two, and no risk of the names drifting out of sync with the files.