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HEIF to FITS Converter

FreeNo uploadNo watermarkBatch support
HEIF FITS
100% private — files never leave your device

High Efficiency Image Format and Flexible Image Transport System exist for different jobs: HEIF is the family container HEIC belongs to — same HEVC-based compression, often used by name on Android and camera firmware where HEIC is the Apple branding. Convert FITS frames to PNG or JPG to preview telescope data, or pack them into a ZIP for sharing.

This converter runs entirely in your browser using WebAssembly — your files never leave your device, nothing is uploaded, and there are no watermarks, sign-ups or queues. Drop in several files at once to convert them as a batch.

How HEIF compares to FITS

HEIF FITS
Compression Lossy HEVC (lossless variant exists) None (optionally Rice/GZIP)
Transparency Supported Not supported
Animation Supported (bursts/sequences) Not supported
Metadata EXIF, depth maps, HDR gain maps Rich text header (WCS)
Best for iPhone photo storage Telescope frames, science data

How to convert HEIF to FITS

  1. 1

    Select your files

    Drag & drop your HEIF files onto the area above, or click to browse. You can add multiple files at once for batch conversion.

  2. 2

    Convert instantly

    Click "Convert to FITS". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.

  3. 3

    Download results

    Download each converted FITS file individually, or grab everything at once as a ZIP archive.

About the HEIF format

HEIC (High Efficiency Image Container) is the HEIF container carrying HEVC-compressed image data, and it has been the default photo format on iPhones since iOS 11. At equivalent quality it stores photos in roughly half the space of JPG, keeps 10-bit color and HDR information intact, and can hold multiple images — bursts,Live Photos pairs, even depth maps — in one file.

Its weakness is everything outside Apple's ecosystem. Windows needs an extension from the Store to preview it natively, many web services still reject the upload, and HEVC's patent licensing slowed hardware adoption on non-Apple devices. Android 9+ phones generally handle it, but the desktop web remained JPG territory for years.

+Strengths

  • ✓About half the size of JPG at the same quality
  • ✓10-bit color and HDR survive the pipeline
  • ✓One file can hold bursts, sequences and depth data

!Limitations

  • −Windows and many web services need extras to open it
  • −HEVC patent licensing complicated adoption outside Apple
  • −Thumbnail and preview performance on old hardware is poor

About the FITS format

FITS (Flexible Image Transport System) has carried professional astronomy data since 1981: every file opens with a plain-text header that records telescope, instrument, exposure, filters and world coordinates, followed by raw pixel arrays — often 16-bit or float, sometimes data cubes.

Values can be negative or far above display range, so FITS never looks right in a photo viewer. Converting to PNG applies a simple scaling pass that reveals the nebula or galaxy in the numbers — good for previews, while science pipelines keep the original.

+Strengths

  • ✓Self-documenting science headers
  • ✓High bit depth (16/32-bit, float)
  • ✓The standard of every observatory

!Limitations

  • −Not display-ready
  • −Files are large and uncompressed

Why convert HEIF to FITS?

Converting makes sense where the strengths of FITS meet what HEIF cannot give you. Self-documenting science headers Meanwhile Windows and many web services need extras to open it One pass through the converter above puts your file on the right side of that trade-off.

Frequently asked questions

Is this HEIF to FITS converter really free?

Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.

Are my files uploaded to a server?

No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.

Does it work on Windows, Mac, iPhone and Android?

Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.

Will I lose quality converting HEIF to FITS?

No — FITS is a lossless format, so every pixel of the converted image matches your original HEIF file. You can also adjust the quality/size balance before converting when the target format supports compression.

Will transparent areas survive the conversion to FITS?

Transparency is kept whenever FITS actually supports an alpha channel. If the target format has none (like JPG), transparent areas are flattened onto a white background — that is a property of the format, not of this tool.

What happens to EXIF data and other metadata?

Conversions here re-encode the image, and re-encoding generally does not carry the original metadata over. If the EXIF data of your HEIF files matters (camera model, GPS, timestamps), keep the original file as the master and treat the converted copy as the shareable version.

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