CalConverters

Image Format Converter

Drop one or more images below to convert them to PNG, JPEG, WebP, BMP, or GIF. Everything runs locally in your browser — nothing is ever uploaded to a server.

Files never leave your device

Drop files here, click to browse, or paste

PNGJPGJPEGWEBPGIFBMPTIFFTIF
80%

The format above is applied to files as you drop them. After a file is done you can pick a different format for it and press Start to re-convert just that one.

What This Tool Does

This converter changes an image from one file format to another — PNG to JPEG, JPEG to WebP, or any combination among PNG, JPEG, WebP, BMP, and GIF. Drop one file or fifty; each one is decoded and re-encoded in the format you choose, and you download the result with a single click.

Everything happens on your device. There's no upload step, no processing queue on a remote server, and no size limit imposed by a backend — the only ceiling is what your browser's memory can hold.

Supported Formats

FormatInputOutputNotes
PNGYesYesLossless, supports transparency. Best for screenshots, logos, and graphics with sharp edges.
JPEGYesYesLossy, no transparency. Smallest files for photos; quality is adjustable.
WebPYesYes (lossless)Modern format, transparency supported. Often smaller than PNG at the same quality.
BMPYesYesUncompressed. Large files, useful for legacy tools that require raw bitmaps.
GIFYesYesLimited to 256 colors. Each conversion here produces a single static frame.
TIFFYes—Input only. Upload a TIFF and convert it to any of the formats above; TIFF isn't offered as an output.

How JPEG Quality Works

JPEG is the only format in this tool with a quality slider (1–100, default 80), because it's the only lossy output here — the others either keep every pixel exactly or aren't re-compressed further. Lower quality values produce smaller files by discarding more fine detail; higher values keep more detail at the cost of file size.

Tip: A quality of 80–85 is usually indistinguishable from the original to the eye while cutting file size substantially. Save quality 95+ for images you plan to zoom into or print.

For a photo you're posting online, 75–85 is a good starting point. For an image that will be edited further or printed large, stay at 90 or above.

Your Files Never Leave Your Device

The conversion runs through a small WebAssembly module loaded into your browser tab. When you drop a file, its bytes are read locally and handed to that module — they're never sent anywhere over the network. Closing the tab discards everything; there's nothing left behind on a server because there was never a server involved in the first place.

If you also need to resize images for a specific platform (App Store icons, social banners, favicons), see the Logo & Image Resizer tools, which use the same on-device approach.

Frequently asked questions

Is this image converter really free?
Yes. There's no sign-up, no watermark, and no limit on how many images you can convert. The tool runs entirely in your browser, so there's no server cost to recoup from you.
Do my images get uploaded anywhere?
No. Every conversion happens locally using WebAssembly running inside your browser tab. Your files never travel over the network, so nothing ever reaches a server.
Can I convert multiple images at once?
Yes. Drop as many files as you like — they're queued and converted one at a time, and each finished file appears as its own downloadable card. Use "Download all" once two or more are ready.
Why is the quality slider only shown for JPEG?
PNG, WebP (lossless), BMP, and GIF in this tool don't discard pixel data, so there's no quality trade-off to tune. JPEG is the one lossy format here, and its slider controls the size-versus-quality balance.
Can I convert a TIFF file?
You can upload a TIFF as your source image, and it will decode and convert correctly. TIFF isn't offered as an output format in this tool, since PNG or WebP cover the same lossless use case with far smaller files and universal browser support.
Will converting to JPEG add a white background to a transparent PNG?
JPEG has no transparency channel, so any transparent areas are flattened against a white background during conversion. If you need to keep transparency, convert to PNG or WebP instead.
What happens if a file fails to convert?
That file's card shows an error message and the rest of your batch keeps processing — one bad or corrupted file never stops the others.