Convert an image (WebP, JPEG, PNG)
Convert your images in a batch to WebP, JPEG or PNG — WebP often halves the weight at equal quality — with transparency handled correctly when you move to JPEG. It is the everyday conversion for getting a site image into the right format. The conversion is local, so an image you convert never leaves your machine.
- 100% local
- Free · no account
- Instant result
This tool runs entirely in your browser — nothing is sent to a server.
Changing an image’s format answers concrete needs: switch to WebP to lighten a site, convert a too-heavy PNG screenshot to JPEG, or get a PNG because a service requires that format. This tool processes several images at once and shows the weight gain achieved for each.
A classic trap deserves to be flagged: JPEG does not handle transparency. Converting a transparent PNG to JPEG replaces the transparent zones with a solid colour — black by default in most tools. Here, you explicitly choose the background colour applied, which avoids unpleasant surprises.
How it works
Type the figures or drop the file you want to process — the tool checks them as you go.
Everything is computed directly in your browser. Nothing is sent to a server.
The result appears instantly, with the detailed breakdown ready to copy, download or keep.
Why use this tool
No account, no download, no limit: the result appears as soon as you enter your data.
Every rule, algorithm and check reflects what we use ourselves every day at Flexina.
The calculations follow the official standards, and the step-by-step detail lets you double-check the outcome.
What does running it locally bring you?
Files, figures and documents never leave your device: nothing is stored, nothing is sent.
Once the page is loaded, you can cut the network: the tool keeps working.
No upload, no account, no third-party server in between: results stay fast and fully private.
Frequently asked questions
Which format to choose?
WebP for the web, in almost all cases: it is lighter than JPEG and handles transparency like PNG. JPEG for maximum compatibility with older software. PNG for screenshots, logos and anything requiring transparency or perfectly sharp outlines.
What happens to transparency in JPEG?
It is replaced by the background colour you choose, since JPEG cannot encode it. To keep the transparency, convert to WebP or PNG instead.
Can I convert several images at once?
Yes, drop as many as you want: each is converted with the same settings and the summary table shows the gain line by line. The “Download all” button then chains the downloads.