The Complete Guide to Converting Image Formats
In short
Format conversion changes the file type without changing what the image shows. Use JPEG for photographs, PNG for screenshots and graphics with transparency, and WebP when you want the smallest file at a given quality and the broadest modern-browser support.
What is image format conversion?
Format conversion re-encodes your image from one container format to another — for example, turning a PNG screenshot into a JPEG to make it smaller, or moving a JPEG photo to WebP for better web performance. The visible content is the same; what changes is how the pixel data is stored, which compression algorithm is used, and which features (transparency, animation, color depth) are available.
JPEG, PNG, WebP — when to use which
- JPEG: Best for photographs and complex natural images. Excellent compression of smooth gradients and continuous tones. Cannot store transparency. Lossy: each save degrades the file slightly.
- PNG: Best for screenshots, logos, illustrations, UI mockups, anything with sharp edges or text. Lossless — every save is identical. Supports full alpha transparency. Files are larger than JPEG for photographic content.
- WebP: The modern all-rounder. Supports both lossy (JPEG-style) and lossless (PNG-style) compression, plus transparency and animation. Lossy WebP is typically 25–35% smaller than JPEG at the same visual quality. Lossless WebP is typically 20–30% smaller than PNG. Supported in all major browsers since 2020.
- Avoid: BMP (uncompressed, huge), TIFF (great archival format but rarely supported on the web), GIF (only useful for short looping animations, and even then animated WebP is better).
How to convert an image
- Upload your image — the tool detects the source format automatically.
- Pick the target format from the dropdown.
- If converting to a lossy format (JPEG or WebP), adjust the quality slider. 80% is a safe default.
- Compare the original and converted versions side by side. The file size of each is shown so you can see the trade-off.
- Click Download to save the converted file. Your original is untouched.
When to convert
- PNG screenshot → JPEG: Useful when you need to email or upload a screenshot somewhere with size limits. Be aware: PNG's sharp text becomes blurry under JPEG compression. Stay above 85% quality.
- JPEG photo → WebP: Cuts file size by 25–35% with no visible quality loss. Ideal for any website where you control the assets.
- Anything → PNG: Use when you need transparency or pixel-perfect quality (e.g. preparing a logo for a designer).
- HEIC/HEIF (iPhone photos) → JPEG: Many older systems and email clients do not display HEIC. Convert to JPEG for universal compatibility.
- GIF → WebP: Animated WebP files are typically 60–90% smaller than the equivalent GIF, with full color support.
- SVG → PNG: When a flat raster file is needed (e.g. for a system that does not render SVG, like some chat apps and email clients).
Conversion tips
- PNG → JPEG warning: JPEG does not support transparency. Transparent areas become solid white in the result. If you need transparency, convert to WebP instead.
- Repeated lossy conversion compounds: Each time you save a JPEG (or lossy WebP), a little quality is lost. Keep a PNG or WebP-lossless master copy and convert from it when you need a lossy version.
- Same-format "conversion" still re-encodes: Loading a JPEG and saving it again as a JPEG is a re-encode. Quality drops slightly even at 100%. Only do this if you are deliberately changing the quality slider.
- Match format to the recipient: Some platforms strip uncommon formats; some email clients still mishandle WebP. When in doubt for general sharing, JPEG is the safest universal choice.
- Watch the alpha channel: Converting a transparent-PNG icon to JPEG ruins it. PNG → WebP keeps transparency. PNG → PNG keeps it too (but no size benefit).
Conversion — common questions
- Will I lose quality when I convert?
- Lossless → lossless conversions (PNG → WebP-lossless, BMP → PNG): no quality loss. Lossy → lossless conversions (JPEG → PNG): no further loss, but the existing JPEG artifacts are now baked in. Anything → lossy (anything → JPEG, anything → WebP-lossy): some loss, controlled by the quality slider. Pick a high quality if you might re-edit later.
- Is WebP safe to use everywhere?
- On the modern web, yes. All major browsers (Chrome, Edge, Firefox, Safari, Opera) have supported it since 2020. Outside the browser, support is improving — recent versions of macOS, Windows 11, iOS, and Android all display WebP natively. The remaining gaps are some email clients and very old systems. For maximum compatibility in those edge cases, fall back to JPEG.
- Why does my JPEG look softer than my PNG original?
- JPEG compression is tuned for photographic content. It is very efficient at storing smooth gradients and continuous tones, but it blurs sharp edges and text — the exact things screenshots and UI mockups have lots of. For sharp-edged content, stay in PNG or WebP-lossless.
- Can I convert to RAW or HDR?
- No. Browser-based tools (including PhotoTools) work with standard 8-bit display formats. RAW formats are camera-specific and contain sensor data that cannot be reconstructed from a finished JPEG/PNG. HDR requires specialized capture and display pipelines. Both need dedicated desktop software.
Privacy: your images stay on your device
Every operation in PhotoTools runs locally in your browser using the HTML5 Canvas API. Your image file is read into memory on your device, transformed there, and the result is generated locally — nothing is ever uploaded to a server. When you close the tab, the image is gone from memory. There is no account, no cloud storage, and no analytics on the file itself.