Try a compatibility roundtrip: Open the practice PNG in Image Converter and save an AVIF copy. Reopen that AVIF, choose PNG and convert again. Both results should remain 1200 × 800. Compare the returned PNG with the original: PNG stores the decoded AVIF pixels but cannot restore detail lost during AVIF encoding. Check that your intended destination accepts the chosen file.
Practice file and tool: Download the synthetic practice file · Open the tool
HEIC: the phone camera format
Keep the moving original: Apple: export a Live Photo as still and movie files
HEIC (High Efficiency Image Container, technically HEIF with HEVC-compressed pictures) is what iPhones have saved photos as since 2017 and what many Android phones offer as an option. It can store a photo in fewer bytes than JPG, depending on the picture and encoder, and can carry extra image data such as a depth map. An Apple Live Photo consists of a still image paired with a separate movie file. Converting its HEIC still to JPG does not convert the motion or sound.
Where compatibility varies: Windows photo applications may need a HEIF/HEVC codec or extension; some upload forms, print services, email clients and older devices do not accept HEIC. Depending on device and transfer settings, sharing or importing may convert it to JPG, while copying or downloading an original can preserve HEIC.
What to do: keep the HEIC as your original — it retains the camera’s original encoding and extra data — and convert a copy to JPG whenever a destination might not understand it. Toolkitta’s converter, compressor and cropper all open HEIC directly and write JPG (or PNG when there is transparency).
AVIF: AV1-based images for the web
AVIF uses AV1 image coding and supports transparency, HDR and wide colour. It can reduce bytes for some images, but comparisons with JPG or WebP depend on the image, encoder and chosen quality. Many current browsers support AVIF; check the target browser, application and file features instead of assuming every destination can open it.
Where compatibility varies: some desktop viewers, email clients, upload forms and design applications do not accept AVIF. Encoding speed also depends on the image, encoder and device; a large photo or batch can take longer than JPG or WebP. Test the actual workflow.
What to do: use AVIF for images on a website you control, ideally with a fallback, and convert to JPG or PNG before sending a file to anyone else.
WebP: lossy or lossless images for the web
WebP offers lossy and lossless compression and transparency. Google reports that lossy WebP images are 25–34% smaller than comparable JPEG images at equivalent SSIM quality in its comparison. This is not a guaranteed saving for every file or a universal ranking against AVIF. WebP is supported by many current browsers and publishing tools; check the intended destination.
Where it breaks: some email clients and older software, and a few upload forms that only list JPG and PNG. If the file will be downloaded and opened by someone in software you do not know, provide a JPG or PNG.
Format and compatibility references: Google: WebP compression comparison · Microsoft: HEIF and HEVC files on Windows · Android: supported media formats
JPG and PNG: widely accepted photo and graphics formats
JPG is widely accepted for photos and PNG for lossless graphics. Either can be larger than alternatives, depending on the image and settings. Even common formats can be rejected by a destination with its own dimensions or byte limits. For anything you hand to another person, a form, a printer or an unknown program, they are still the right answer.
The two-question rule
- Who will open it? If it is a website you control, use WebP (or AVIF with a WebP or JPG fallback). If it is a person, a form, an email or a printer, use JPG for photos and PNG for graphics with transparency or sharp text.
- Will you edit it again? Keep a lossless or original master (HEIC from the camera, PNG for graphics, the original RAW if you have one) and convert copies from that, so each conversion starts from the best source rather than from a previous lossy copy.
A practical workflow: leave the originals as they are, convert to JPG or PNG when sharing, and convert to WebP when publishing. If size limits apply, run the converted file through the compressor with a target.
What conversion does and does not change
- Quality: converting between lossy formats re-encodes the picture and can change detail. Quality numbers are not comparable between codecs. Start from the original and inspect the result.
- Transparency: JPG has none. Converting a transparent PNG, WebP, AVIF or HEIC to JPG fills the transparent areas with a background colour.
- Metadata: Re-encoded copies usually omit camera tags, but same-format or original-kept paths may retain metadata. Use Remove Image Metadata and inspect the downloaded copy when that is the goal.
- Animation: only the first frame of an animated GIF, WebP or AVIF is converted.
- Orientation: supported phone-photo rotation tags are applied while decoding. Inspect the result before sharing; some formats or decoders can handle orientation differently.