Convert HEIC photos without losing the originals

Give the original and the upload different homes

Create a folder called Photo-conversion with two subfolders: Originals and JPEG-for-sharing. These are suggested names, not application controls. Copy loose HEIC files into Originals; leave the source files where they are. Put this project outside a shared folder so an unfinished export cannot accidentally become the delivered picture.

If these are irreplaceable photographs, make a second copy of the originals on separate storage before working. Two folders on the same disk help prevent mix-ups but cannot protect against that disk failing. Keep the original filenames where possible; a matching stem such as IMG_4281 makes the HEIC and JPEG easier to pair later.

Do not change .heic to .jpg by renaming. That changes the label, not the encoded picture. Nor does “without losing the originals” mean a JPEG conversion is lossless. JPEG is a compressed delivery format; preserving the HEIC is what gives you a route back to the source.

For a loose HEIC file, export one JPEG in Preview

1. In Finder, Control-click the HEIC copy in Originals and choose Open With → Preview. Check that the photograph shown is the one you intend to send.
2. Choose File → Export. In the export dialog, set Format to JPEG. Apple's conversion instructions document this route and its quality adjustment.
3. Start with a high Quality setting. Choose JPEG-for-sharing as the destination and a recognizable name, such as IMG_4281-upload.jpg. Click Save.

Expect a new JPEG in the destination folder, with the HEIC still present in Originals. Open the JPEG from Finder rather than assuming the picture already on screen is the export. If you see a replacement warning, cancel and choose an unused filename or a fresh destination folder. There is no need to overwrite an earlier export.

If the desired format is absent, Apple documents holding Option while opening the Format menu to reveal additional formats. Check that you chose Export rather than a rename command. If Preview cannot open the HEIC itself, return to the source and obtain another copy; a different extension will not repair an incomplete download.

For ordinary photo uploads, choose JPEG rather than JPEG-2000. If the website imposes a file-size limit, first inspect the exported file's size. Reduce quality in a new export only if needed, always starting again from the HEIC. Repeatedly converting the previous JPEG creates an unnecessary chain of compressed copies.

For a Photos library, preserve first and convert second

A picture inside Photos needs an explicit export. Do not browse inside the Photos Library package or move its internal files. Select one representative picture in Photos before attempting a whole album.

1. Choose File → Export → Export Unmodified Original. Keep its filename, click Export, select Originals and click Export Originals. This retrieves the imported format; an original HEIC remains HEIC.
2. If you want assigned IPTC metadata and keywords alongside the original, select Export IPTC as XMP during that export. Keep the resulting sidecar with the photograph.
3. Select the same picture again. Choose File → Export → Export [number] Photos and set Photo Kind to JPEG. Expand the arrow beside Photo Kind for quality and size options. Retain full dimensions for your first copy unless the destination requires smaller ones.
4. Export to JPEG-for-sharing. Open the saved JPEG and compare its appearance with the selected library picture, including any crop or adjustments you wanted to deliver.

Apple's Photos export guide distinguishes original-format exports from selected-format exports. A Live Photo's unmodified export has separate still and video files; retain both. The JPEG is a still, so it cannot preserve the motion experience.

If an original export does not complete, leave the library intact. Check available disk space and connectivity if originals must arrive from iCloud, then retry one picture into a new folder. An empty destination or partial batch is a reason to pause, not a reason to delete library items.

Check the copy against the job

Open both the HEIC and JPEG in Preview. Inspect fine detail, edges, shadows, orientation and skin tones. Zoom in far enough to notice distracting compression, then return to the size at which the recipient will use the photograph. A plausible thumbnail alone is a weak check.

Click Preview's Info button to open Inspector. Apple's information guide describes the General info and More info tools. Compare the available dimensions, file type and file size for each file; inspect metadata you need rather than assuming it survived.

For a hypothetical example, a 4032 × 3024 source and a 4032 × 3024 JPEG have matching pixel dimensions. That does not establish identical image quality or matching metadata. A smaller byte count does not establish that either. If the JPEG is unexpectedly small in dimensions, review the export's size choice and repeat from the original.

Try the JPEG in the actual destination before converting everything. A successful local opening does not prove a particular upload form accepts it. If a form still rejects it, read its requirements for format, dimensions and maximum bytes, and change only the relevant setting. Keep each trial separate until one passes.

Conversion is also not a privacy check. Review location information and anything visible in the photograph before sharing. Apple's HEIF guidance explains format compatibility; choosing a compatible format alone does not establish what personal information accompanies the file.

Scale up only after one pair passes

For a batch of loose files, Apple supports opening several pictures in one Preview window, selecting them in its sidebar and following the export procedure. Work in manageable groups and choose a new destination for each group. Compare the expected pictures with the outputs; check several exports rather than trusting a completed dialog.

Keep a short note of which source group produced each output folder. Filename collisions are easier to resolve before merging folders. With Photos, count pictures separately from files because Live Photo components and XMP sidecars can legitimately increase the original-export file count.

If a JPEG looks wrong, delete only that disposable export and repeat from the HEIC with revised settings. If an original has been deleted or overwritten, stop making changes and recover it from your separate backup or the intact source library. Converting the JPEG back to HEIC cannot reconstruct information already lost.

After the upload succeeds, retain the originals and their backup. Remove unwanted trial JPEGs once you have identified the final delivery. A neat conversion folder should make tomorrow's decision easy: which file is the source, which copy was sent, and where the source can be recovered.