Image Format Converter
Drop one file or a whole batch. Pick a target format, dial in the quality, and see the before/after instantly. Nothing is uploaded — your files never leave your device.
Convert image format
Updates liveWhich format should I pick?
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Does the image have transparency?Yes → WebP (smaller) or PNG (widest support). Skip JPEG — it will flatten transparency to white.
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Is it a photograph (continuous-tone colour)?Yes → WebP at quality 80–85 for the smallest file, or JPEG for broadest compatibility.
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Is it a logo, icon, UI screenshot, or line art?Yes → PNG or lossless WebP. Flat colours and sharp edges compress badly with JPEG (expect ringing artefacts around text).
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Do you need maximum compatibility with old tools?Yes → JPEG for photos, PNG for everything else. BMP only if something explicitly requires it.
Format comparison
| Format | Compression | Transparency | Best for | Typical size vs PNG | Browser support |
|---|---|---|---|---|---|
| PNG | Lossless | Yes (full alpha) | Logos, icons, UI, line art | 100% (baseline) | Universal |
| JPEG | Lossy | No | Photographs | ~15–30% (photos) | Universal |
| WebP | Lossy or lossless | Yes | The modern default for the web | ~10–20% lossy · ~70% lossless | All modern browsers |
| BMP | None | Rarely | Legacy Windows tooling | ~300–400% (uncompressed) | Universal, but inefficient |
Size ranges are approximate and depend on image content. A photograph at JPEG quality 85 typically weighs 15–25% of its PNG equivalent; the same photograph at WebP quality 85 typically weighs 10–18%. Simple graphics (solid colours, sharp edges) compress better with lossless formats than lossy ones.
How It Works
PNG is lossless and supports transparency. Every pixel is preserved exactly, which makes it ideal for logos, icons, UI screenshots, and any graphic with flat colours or sharp edges. The trade-off: photographs as PNG are enormous.
JPEG uses lossy compression tuned for natural images. It discards fine detail the human eye doesn't notice, producing tiny files from photographs. JPEG has no transparency — if the source has an alpha channel, transparent areas get flattened (this tool flattens them to white).
WebP is the modern compromise. It supports both lossless and lossy modes, handles transparency, and typically produces files 25–35% smaller than JPEG at equal visual quality. Every modern browser supports it. For most new content, WebP is the right answer.
BMP stores raw uncompressed pixels. It is almost never the right choice on the web, but occasionally needed for legacy Windows tooling.
All conversion happens client-side via the Canvas API. Your image is decoded, redrawn to a canvas, and re-encoded in the target format — all in the browser, with nothing sent to a server.
Tips & Best Practices
Frequently Asked Questions
Is my image uploaded anywhere?
No. All conversion happens entirely in your browser using the Canvas API. Your images are never sent to a server and never leave your device. The tool works even if you disconnect from the internet after the page loads.
Which format should I pick?
For photos on the web, use WebP at quality 80–85 for the smallest files. For logos, icons, and graphics with transparency, use PNG or lossless WebP. Choose JPEG only when you need maximum compatibility with older tooling. Avoid BMP unless a specific legacy workflow requires it.
Why is my converted WebP bigger than the original JPEG?
This can happen if you convert with very high quality (95+) or if the source JPEG is already aggressively compressed. WebP compresses better than JPEG at equivalent perceptual quality, but forcing near-lossless quality negates that advantage. Try quality 80–85, or if you specifically need lossless output, be aware that lossless WebP of a photograph will often be larger than a compressed JPEG.
Why is transparency lost when I convert to JPEG?
JPEG has no alpha channel — it's a format designed for photographs, where transparency isn't needed. If your source has transparent areas (common in PNGs of logos or UI screenshots), this tool fills them with white during conversion. To preserve transparency, convert to WebP or PNG instead.
What does the quality slider actually do?
For lossy formats (JPEG and WebP), the quality slider controls the encoder's tolerance for discarding detail. Higher quality means less discarded detail but a larger file. Quality 100 is near-lossless but often much larger than 90 for no perceptible gain. For PNG and BMP the slider is hidden, because those formats don't use lossy compression.
Is EXIF / metadata preserved?
No. The Canvas re-encode strips all EXIF and metadata by default, including camera info, GPS coordinates, and editing history. This is usually a privacy win, but if you need to keep metadata (e.g. photographer attribution), use a dedicated tool that preserves it.
Does this tool re-orient rotated photos?
Yes. Photos from phones often store orientation in EXIF rather than rotating the pixels themselves. The tool uses the modern createImageBitmap API with imageOrientation: "from-image" to bake the correct orientation into the output, so portrait-mode iPhone photos export right-way-up.
What is the maximum file size I can convert?
Since processing is in-browser, the limit is your device memory. Most modern desktops handle 50 MB+ images without issue; mobile devices may struggle above 20 MB. If a conversion hangs on a very large file, the browser is likely out of memory — resize the image first and then convert.
Can I convert multiple images at once?
Yes. Drop multiple files onto the upload zone, paste several at once, or select multiple files in the file picker. Each appears in the batch list; switch between them to preview. Use "Download all (.zip)" to grab every converted file as a single archive.
Why do PNG files have no quality slider?
PNG uses lossless compression — it never discards pixel data — so there's no quality setting. The output is always a pixel-perfect copy of the input at the chosen format. BMP is similar: it stores raw uncompressed pixels, with no compression settings to tune.