How big is a CRW file versus the HEIC output?

CRW is Canon's original RAW format, used from 1997 through 2004 on bodies including the D30, D60, 10D, 300D Digital Rebel, EOS-1D, EOS-1Ds, and the PowerShot Pro 1, Pro 70, and G-series compacts up to the G6. Photographers digitizing old hard drives, estate executors recovering a deceased relative's archive, and museum collections cataloging early-digital photojournalism convert CRW to HEIC to produce a modern, space-efficient viewing archive: HEIC is readable by every current Apple device and stores the same image at roughly half the size of JPG.

Canon dropped CRW for the TIFF-based CR2 with the EOS-1D Mark II in 2004, so any CRW file is at least two decades old. The format is a 12-bit Canon-proprietary container (CIFF-based) holding sensor data from 3MP to 11MP depending on body - tiny by modern standards. A 6MP 10D CRW is roughly 8MB; converted to high-quality HEIC it lands around 1-1.5MB, small enough that an entire early-2000s career archive fits comfortably in an iCloud or Google Photos library (both services accept and index HEIC natively) with face recognition and date search working across it.

The metadata is often the value in these archives - a 2003 press-pool CRW is small but historically rich. CRW to HEIC batch conversion preserves the EXIF timestamp, shutter, lens, and ISO so files remain searchable after conversion. Two caveats for archivists: HEIC is a lossy derivative, so keep the CRW originals (or DNG conversions) as preservation masters, and institutions distributing to Windows-heavy user bases should remember those machines need the HEVC codec - our HEIC to JPG tool covers that gap on demand.

Reasons to convert CRW to HEIC usually come down to compatibility, file-size, or specific feature requirements. Common situations:

• An app or platform only accepts HEIC uploads.
• You need a feature unique to HEIC (e.g. transparency, vector scaling, animation, multi-page pages, etc.) that CRW doesn't provide.
• You're optimising file size — modern formats often produce smaller files than the older format you started with.
• You need a single archival format across a project so files behave consistently in the same viewer.

1. Open the CRW → HEIC tool on heic.now.
2. Drag your CRW file onto the drop zone, or click Select files. You can drop a whole folder of files at once.
3. The output is fixed to HEIC. If the format supports extra options (page size, transparency background, quality, EXIF stripping), tweak them in the right-hand panel.
4. Click Convert. The job runs on our server and finishes in a few seconds for typical photos.
5. Download the result. Files stay in storage for 24 hours and are then permanently deleted.

The entire flow is free for the first 10 jobs per day with no signup required. A free account doubles that quota; a premium plan removes the limit entirely.

• Convert to DNG first via Adobe DNG Converter 14+ for your archival master, then derive HEIC from the DNG for the everyday browsing copy - this future-proofs the original.
• Use a high quality setting on conversion - CRW sources are only 3-11MP, so the HEIC output is tiny anyway and there's no reason to squeeze it further.
• Check EXIF timestamps before converting - early CRW bodies had clock drift and wrong dates that ExifTool's -AllDates argument can fix in batch.
• Don't trust embedded thumbnails as quality indicators - CRW thumbs are 160x120 JPEGs that look terrible but the underlying 6MP data is fine.
• HEIC keeps the full EXIF through conversion - timestamps, camera model, and lens data stay searchable in Apple Photos, Google Photos, and DAM software.