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NexConvert — Local & Private

Stop uploading images just to change the format.

You have a folder of PNGs that need to be WebP for your website. Or a batch of WebPs that a client needs as JPEGs. Every online converter wants you to upload them one at a time, wait, download, repeat. NexConvert handles the whole folder at once — locally, in your browser, with no queue and no file size cap.

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How to convert images offline

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Select Files

Select or drag raw images of any format into the workspace.

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Select Format

Choose output format (JPG, PNG, WebP) and define quality options.

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Batch Export

Click convert and download the converted files as a clean ZIP package.

How it works

Your browser already knows how to decode and re-encode images through the Canvas API. NexConvert just gives you a proper interface for it.

Every format combination

JPG to WebP, PNG to JPG, WebP to PNG — any direction. Drop a mixed folder and convert everything to one target format in a single operation. Adjust quality for JPG and WebP output with a slider.

Transparency handled correctly

Converting to PNG? Alpha channels are preserved exactly. You won't end up with a white rectangle where your transparent logo used to be. Converting from PNG to JPG? The background is filled cleanly instead of turning black.

No upload, no sign-up, no daily limit

Most free converters cap at 5MB or 20 files per day. NexConvert has no limits because there's no server involved — it's just your CPU doing the work. The only practical ceiling is your browser's available memory.

Works offline after first visit

NexConvert is a Progressive Web App. Load it once, and it works without an internet connection going forward. Pin it to your dock or home screen and it behaves like a native app.

Frequently Asked Questions

Everything you need to know about NexConvert format conversion.

How does browser-based image conversion work?

It uses the HTML5 Canvas API in your browser to decode the uploaded image format (like PNG, JPG, or WebP) and re-encode it directly to your desired target format. The process executes locally on your CPU.

Will image transparency be preserved during conversion?

Yes. If converting to PNG or WebP, transparency is fully preserved. When converting transparent images to JPEG (which does not support alpha channels), transparency is cleanly filled with a solid white background.

How many files can I convert at once?

You can select and convert dozens or hundreds of files simultaneously. Since processing occurs locally on your machine, there are no cloud queuing delays or daily caps.

Are my files safe during format conversion?

Completely. Because the utility runs purely inside your browser client without server-side uploads, your photos never leave your device.

Ready to convert your images?

Drop your files at the top of the page. Runs in any modern browser offline.

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