Convert
PNG to HEIC Converter
Convert PNG images to HEIC with transparency handled on purpose: flatten onto a colour you pick, or keep alpha. Screenshots and text are flagged first.
Input
Drop PNG files here
or choose them from your device
PNG · up to 100 MB per file · processed on your device
At a glance
- Reads from your PNG
- Colour type, transparency share, distinct colours, content type
- Transparency
- Flatten onto a colour you pick (default) or keep alpha (experimental)
- Warns about
- Screenshots and UI graphics that HEIC will soften
- Encoder
- HEVC, fixed QP 25, 8-bit 4:2:0
What this tool does
PNG and HEIC are built for different material, and this page tells you which kind your file is before converting. It measures the PNG's pixels: colour type, how much is transparent or partly transparent, how many distinct colours there are, and whether the picture looks photographic or like a screenshot. A photographic PNG converts well, because lossless PNGs of photos are large. On our 800×600 test photo the HEIC was 59.3 KB from 907.5 KB, 7% of the original.
Screenshots, diagrams and UI graphics are the exception. HEIC splits the image into blocks, discards fine detail and stores colour at half resolution, which softens thin lines and text. On a 900×500 test screenshot with 392 colours, the HEIC was still 77% of the PNG's size (58.2 KB from 75.4 KB), so the saving was modest, and when we compared pixels, 0.4% of them moved by more than 16 levels (the worst by 86 of 255), concentrated on letter edges. The tool flags such images before conversion; keep them as PNG, or use lossless WebP, when the text must stay crisp.
Transparency is handled on purpose. HEIC photos are normally opaque, so the default is to flatten transparent areas onto a colour you choose: white, black, a custom colour, a pixel picked from one of the four corners, or a pixel you click on a checkerboard preview. This avoids the black that many apps show where alpha is ignored. An opt-in Keep transparency instead (experimental) stores alpha as a separate auxiliary image. It reads back correctly in libheif and pillow-heif, but support elsewhere varies, so test it in the apps you care about.
How to use it
- 01
Add PNG files
Drop PNGs on the upload area or use Add files. A JPG or WebP dropped here is flagged with a link to its own page and a Convert anyway button.
- 02
Read the analysis
The This PNG panel shows colour type and bit depth, whether transparency is present and how much (for example '49% clear, 51% partly clear'), the colour space, distinct colours and a content verdict.
- 03
Handle transparency
If the PNG has transparency, choose the Fill transparent areas with colour using White, Black, Custom, a corner pixel or a click on the preview. Or switch on Keep transparency instead (experimental).
- 04
Heed screenshot warnings, then convert
If the tool says 'This looks like a screenshot or UI graphic', decide whether the size saving is worth the softening. Press Convert N files to HEIC when ready.
- 05
Check the measured result
Each result shows the size ratio and, for flattened files, the colour used, for example 'transparency flattened onto #ffffff'.
When to use it
Photographs that were saved as PNG
Photos exported as PNG by design software or screenshots of photos shrink the most, as our 907.5 KB test photo shows (7%).
A logo or cut-out that must sit on a coloured background
Flatten onto the brand colour, picking it from a corner pixel, and get a HEIC that looks right in apps that ignore transparency.
Testing how HEIC alpha behaves
Turn on Keep transparency to produce a HEIC with an auxiliary alpha plane and see which of your viewers honour it.
Good to know
- 01Text, thin lines and flat-colour graphics soften, and no setting prevents it, because the encoder runs at a fixed QP of 25 in 8-bit 4:2:0.
- 02Keep transparency is experimental. The alpha is stored as a HEIF auxiliary image that libheif and pillow-heif read; other apps may ignore it and show black where the PNG was clear.
- 03Animated PNG (APNG) becomes a single still image. A frame picker lets you choose which frame; the animation is not kept.
- 0416-bit PNGs are reduced to 8-bit because the browser decodes to 8-bit and the HEIC is 8-bit. Palette PNGs with transparency and greyscale-with-alpha PNGs are read correctly.
- 05The HEIC is tagged sRGB and other PNG metadata is not carried.
- 06Limits: 100 MB and 100 megapixels per file; 50 files per run. Windows and many non-Apple apps need support for HEIC to open the result.
Privacy and limits
Your file stays on your device
This tool runs in your browser with WebAssembly. The file is read into the tab, processed there and discarded when you close it — there is no upload and no account. You can check this yourself in your browser's network panel, and the privacy page lists what analytics does and does not receive.
Limits and checks
Up to 100 MB and 100 megapixels per file; batches of up to 50 files and 500 MB. Files are treated as untrusted input and every output is re-opened and validated before it is offered — see how we handle untrusted files.
Frequently asked questions
Related tools and reading
Further reading
Last updated: . Something wrong or out of date? Tell us — corrections are recorded in the changelog.