Different image formats exist because different use cases have different requirements — compression, transparency, animation, colour depth. Choosing the wrong format can mean unnecessarily large files, missing transparency, or compatibility problems.
The Main Image Formats Explained
JPG (JPEG)
Best for: Photographs, complex images with gradients, anything without a transparent background
How it works: JPG uses lossy compression. It achieves small file sizes by discarding fine detail the eye barely notices. The compression level is adjustable — higher quality means larger files.
Not ideal for: Graphics with solid colours, text, logos, images that need transparency
PNG
Best for: Screenshots, logos, graphics with transparency, images with sharp edges and solid colours
How it works: PNG uses lossless compression. Every pixel is preserved exactly. PNG files are larger than JPG for photos but often smaller for flat-colour graphics.
Not ideal for: Full-colour photographs (files become unnecessarily large)
WebP
Best for: Web images — replaces both JPG and PNG with better compression
How it works: Supports both lossy and lossless modes, plus transparency and animation. Produces files ~25–34% smaller than JPG or PNG at equivalent quality.
Not ideal for: Legacy software, email clients, or recipients using older applications
HEIC/HEIF
Best for: iPhone and iPad photos — significantly smaller than JPG
How it works: Uses the H.265 video codec for still images. Very efficient compression.
Not ideal for: Sharing with non-Apple users or web use — limited compatibility
GIF
Best for: Simple animations, icons with limited colours
How it works: Lossless, but limited to 256 colours per frame. Very old format.
Not ideal for: Photographs, complex images, or modern animations (WebP or video are better)
SVG
Best for: Logos, icons, illustrations — any image that needs to scale perfectly at any size
How it works: Describes images as mathematical paths rather than pixels. Resolution-independent.
Not ideal for: Photographs — SVG is a vector format, not suited for raster photos
Quick Format Selection Guide
| Situation | Best format | |---|---| | Sharing a photo via messaging | JPG | | Website product photo | WebP (with JPG fallback) | | Logo on a website | SVG or PNG (with transparency) | | Screenshot | PNG | | iPhone photo (to share widely) | Convert HEIC → JPG | | Animated image | WebP or GIF | | Image for editing | PNG (lossless, preserves quality) |
How to Convert Between Formats with ToolzStack
General purpose conversion
Image Converter accepts most image formats and converts between JPG, PNG, WebP, HEIC, GIF, BMP, TIFF, and more. Upload your file, select the target format, download.
Specific conversions
For common conversions, ToolzStack has dedicated tools optimised for each pair:
Quality and File Size Considerations
Every time you convert from a lossy format (JPG, WebP lossy) to another lossy format, you introduce a small amount of additional quality loss from re-encoding. For most purposes this is not visible.
To avoid accumulating quality loss across multiple conversions:
- Keep your original source files (originals from camera or design software)
- Export to a lossless format (PNG) when you need an editing intermediate
- Export to the target lossy format (JPG/WebP) as the final step
Related guides: What is a WebP File? · How to Convert HEIC to JPG