Zokilos

Image Format Converter

Convert between JPG, PNG, WEBP, BMP, GIF, TIFF & ICO — with the exact size change shown

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Click to choose a file, or drag it here
JPG, PNG, WEBP, BMP, GIF, or TIFF — HEIC not yet supported
Quality (JPG/WEBP only) 85
original
converted

What Is an Image Format Converter?

An image format converter changes an image from one file type to another — JPG to PNG, PNG to WEBP, and so on — and this one shows you exactly how the file size changed as a result, not just the converted file.

How to Convert an Image

1

Upload your image.

2

Pick the format to convert to, and quality if it applies.

3

Press "Convert Image" and see the size change before downloading.

Supported Formats

  • JPG / JPEG — small, lossy, no transparency
  • PNG — lossless, supports transparency
  • WEBP — modern, small, supports transparency
  • BMP — uncompressed, large files
  • GIF — 256 colors, supports simple animation frames as a static image
  • TIFF — lossless, common in print and scanning
  • ICO — multi-size icon format

Why the File Size Changes

Every format compresses (or doesn't) differently. Converting a compressed JPG to an uncompressed BMP will almost always make the file bigger; converting a PNG screenshot to WEBP will usually make it smaller. The result banner shows the exact percentage change every time, whichever direction it goes.

What the Quality Slider Does

It only affects JPG and WEBP output — the two lossy formats here. Lower quality means a smaller file with more visible compression artifacts. PNG, BMP, GIF, TIFF, and ICO don't use a quality setting the same way, so the slider doesn't change their output.

Does This Support HEIC?

Not yet. HEIC (the format iPhones save photos in by default) needs an extra decoding library this tool doesn't currently include. Export or share the photo as JPG from your phone first, then convert it here if needed.

When You'd Use This

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Web-ready images

Convert to WEBP or optimized JPG for faster-loading pages.

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Compatibility

Convert to a format an older tool or platform actually accepts.

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Transparency

Convert to PNG or WEBP when you need a transparent background preserved.

Is My Image Stored Anywhere?

No — your image is processed for that one request and never stored. No account or sign-up is required to use it.

Limitations

  • No HEIC input or output
  • One image at a time, no batch conversion
  • Animated GIFs convert as a single static frame

Benefits of Using This Tool

  • 7 output formats covering the vast majority of real-world use cases
  • Shows the exact size change as a percentage, not just the file
  • Free, no sign-up, nothing stored

Frequently Asked Questions

What image formats are supported?

Output to JPG, PNG, WEBP, BMP, GIF, TIFF, or ICO. Upload almost any common image format as the source, including JPG, PNG, WEBP, BMP, GIF, and TIFF.

Does this support HEIC (iPhone photos)?

Not yet. HEIC needs an extra decoding library this tool doesn't currently include, so HEIC files aren't supported as input or output right now.

Why did my file get bigger after converting?

Some formats are inherently less efficient than others — converting a compressed JPG to an uncompressed BMP, for example, will almost always produce a larger file. The percentage shown after converting tells you exactly what happened, bigger or smaller.

What does the quality slider affect?

It only affects JPG and WEBP output, since those are the only lossy formats here — lower quality means a smaller file with more compression artifacts. PNG, BMP, GIF, TIFF, and ICO output ignores it, since those formats don't work that way.

Is my image uploaded and stored somewhere?

Your image is processed for that one request and never stored.

Just want a smaller file, same format? Try the Image Compressor.