JP2 to HEIC Converter
Convert JP2 to HEIC in your browser. JP2 files usually come from libraries and digital archives, medical (DICOM) and satellite imaging, and digital cinema packages; HEIC is the better fit for storing photos on Apple devices. You get a HEIF file whose picture is JPEG-compressed rather than HEVC, because no HEVC encoder runs in a browser. Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
JP2 expected · other image formats also work
How to use JP2 to HEIC
- 1
Add your JP2 files: drop them here, choose them, or paste from the clipboard.
- 2
Pick the colour that replaces transparent areas, since HEIC has none.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .heic files one at a time or together as a ZIP.
Why use Aback Images for jp2 to heic
Where the HEIC goes next
HEIC opens in Apple devices, recent Android phones, and Windows with the HEIF and HEVC extensions.
HEIC next to JP2
A lossy HEIC usually comes out far smaller than the JP2, which stores wavelet coding: reversible 5/3 for lossless files, irreversible 9/7 for lossy ones.
The first lossy pass
The JP2 holds up to 16 bits per channel is common, more is possible with nothing discarded yet. This conversion is the first lossy encode these pixels see, and hard edges and flat colour show it first.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
JP2 vs HEIC
What changes from JP2 to HEIC
Encoding: the JP2 uses wavelet coding: reversible 5/3 for lossless files, irreversible 9/7 for lossy ones; HEIC uses lossy HEVC (H.265) intra coding, on iPhones as a grid of 512×512 tiles, and the download is a HEIF file whose picture is JPEG-compressed rather than HEVC, because no HEVC encoder runs in a browser.
Bit depth: up to 16 bits per channel is common, more is possible in the JP2; HEIC allows 8 or 10 bits per channel, and the HEIC written here has 8 bits per channel. 12 and 16-bit JPEG 2000 files are reduced to 8 bits per channel.
Colour: sRGB, greyscale, YCC or a space described by an ICC profile in the JP2; HEIC supports YCbCr, usually tagged Display P3 on iPhones, written here as 8-bit sRGB.
Transparency: the JP2 stores it as an extra component flagged as opacity; HEIC could hold it as an auxiliary image item, rarely used by cameras, but this writer flattens it, so transparent areas are filled with the colour you choose.
Metadata: the JP2 can carry XML, ICC and resolution boxes; HEIC can carry EXIF, XMP and an ICC profile, stored as items, but nothing is copied across.
About JP2
JPEG 2000 is a wavelet-based format that can be truly lossless or lossy, handles very high bit depths and huge images, and is used where long-term fidelity matters: archives, medicine, satellites and digital cinema.
A .jp2 file is a box structure: a 12-byte signature box, an 'ftyp' box, a 'jp2h' header box with the size and colour specification, then the 'jp2c' box holding the codestream, which begins with FF 4F FF 51.
JP2 files usually come from libraries and digital archives, medical (DICOM) and satellite imaging, and digital cinema packages.
About HEIC
HEIC is the default photo format on iPhones and many Android phones. It is about half the size of JPEG, but Windows, many websites and older software cannot open it without converting.
A HEIC is a HEIF file (ISO base media boxes with the brand 'heic'). iPhone photos store the picture as a grid of 512×512 HEVC tiles that the decoder stitches together, with the thumbnail, depth map and HDR gain map as further items.
When converting JP2 to HEIC makes sense
HEIC is the better choice for storing photos on Apple devices, while JP2 suits archival masters and specialist imaging.
HEIC strengths: About half the size of JPEG; Stores depth maps, Live Photos and HDR. Drawbacks to weigh: Not supported by most websites and Windows apps; Patent-encumbered codec.
Limitations
- A JPEG 2000 file may be a lossless master or a lossy derivative; the file does not tell you which at a glance, so keep the original either way.
- Archival scans can be tens of thousands of pixels across, and decoding them needs a lot of memory on a phone.
- The file is a valid HEIF, but its picture is JPEG-coded rather than HEVC, so apps that expect HEVC (Apple Photos, Windows' HEVC extension) may not open it.
- The picture inside is JPEG-coded, so the file is about the size of a JPG at the same quality rather than the half size of a camera HEIC.
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Frequently asked questions
Does converting JP2 to HEIC lose quality?
HEIC is lossy, so detail the eye barely notices is discarded to save space. 12 and 16-bit JPEG 2000 files are reduced to 8 bits per channel.
What happens to transparency when converting JP2 to HEIC?
JP2 stores transparency as an extra component flagged as opacity. HEIC has no alpha channel, so transparent pixels are composited onto a solid colour, white unless you pick another. To keep transparency, convert to PNG, WebP or AVIF instead.
Will the HEIC open in Apple Photos?
Not always. The file is a valid HEIF container, but its picture is JPEG-compressed rather than HEVC, because no HEVC encoder can run in a browser. libheif-based apps such as GIMP, darktable and ImageMagick open it; Apple Photos and Windows' HEVC extension expect HEVC and may refuse it. For an iPhone, JPG is the safer choice.
Which apps open HEIC files?
Apple devices, recent Android phones, and Windows with the HEIF and HEVC extensions. It opens in Safari on recent Apple systems; other browsers do not display it.
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.