For most iPhone HEIC photos, set JPEG quality between a few values on the 0-100 scale. You get a file that looks nearly identical to the original. The size stays manageable. Go above a certain point and files balloon for almost no visible gain. Quality 100 does not make a JPG lossless. Control both the appearance and the storage footprint of your converted photos by understanding this scale.
Understanding the JPEG Quality Scale
JPEG quality runs on a 0-100 scale. Higher values mean less data discarded and bigger files. Lower values mean more data discarded, smaller files, and visible blocky artifacts. The scale is not linear. At a certain point, a lot of detail the eye cannot easily see is gone. At a higher point, almost all visible detail remains but file size grows fast. Quality 100 discards very little data, yet it is still lossy and often produces much larger files for little visible gain.
When you convert HEIC to JPG, you perform a lossy re-encode. Each conversion adds a small amount of loss. Convert from the original HEIC file, not from an earlier JPG. This avoids stacking losses.
Recommended Quality Settings for Different Uses
Everyday Sharing and Archiving
Pick a quality in the middle range. Photos look nearly identical to the source. File sizes stay reasonable. Use this for social media, messaging, and long-term storage.
Printing and Editing Headroom
Dial it up to a higher range for moderate-sized prints or when you want extra data for later edits. Files get noticeably larger.
When to Skip Quality 100
Avoid 100 unless you have a specific need for the least data removal possible. The file size increase is large and the visible improvement over a slightly lower setting is minimal.
If you must keep every bit of original data, JPEG is the wrong format. Output to PNG instead. It is lossless but far larger than JPG for photographs.
Why the JPG Ends Up Larger Than the HEIC
HEIF photos can take up to about half the storage of equivalent JPEG photos. HEIC, the iPhone's HEIF container, uses a more efficient algorithm than JPEG. When you convert HEIC to JPG, you move to a less efficient format. The JPG file is often larger than the original HEIC, even at similar quality levels. This is normal. The larger JPG file size is a direct consequence of the different methods.
A 12-megapixel iPhone photo measures 4032 by 3024 pixels. At a moderate JPEG quality, the file might be two to three times the size of the original HEIC. At quality 100, the difference grows further. Choosing a lower quality setting keeps file sizes reasonable.
Comparing JPEG Quality 80 vs 100
When choosing between quality 80 and 100, the practical difference in visible quality is tiny for most photos. Quality 80 removes fine details that are hard to see on screens and in prints up to 8x10 inches. Quality 100 preserves nearly all of those details. The file size can be two to four times larger.
Unless you print very large, over a certain size, or need to perform heavy edits later, quality 80-90 is sufficient. At a moderate setting, the data removal is aggressive enough to save space but gentle enough to look clean. Quality 100 is rarely worth the storage cost.
When to Use PNG Instead of JPG
PNG output is lossless. No data is discarded during conversion. This makes PNG ideal for images you will edit multiple times, for graphics with text or sharp lines, or when you need to convert HEIC without losing quality in the strictest sense. But PNG is far larger than JPG for photographs. A single 12-megapixel photo saved as PNG can be much larger. A moderate-quality JPG of the same photo runs much smaller.
Use PNG when:
- You plan to edit the photo repeatedly and want to avoid cumulative loss.
- The image contains text, diagrams, or screenshots where sharp edges matter.
- Storage space is not a concern.
For typical photo sharing and archiving, JPEG at a moderate quality offers a better balance.
How to Convert with the Right Quality Setting
Step-by-Step Conversion
- Open your conversion tool and select the original HEIC file. Do not use a JPG that was converted earlier.
- Find the quality or compression setting. It may be a slider, a dropdown, or a number field.
- Set the quality to a solid middle value in the recommended range. Need smaller files? Try a lower setting. Need higher fidelity? Try a higher setting.
- Preview the output if the tool offers it. Check that the photo looks clean with no blocky artifacts.
- Convert and save the JPG. Check the file size. If it is much larger than expected, reduce the quality slightly.
The same principles apply regardless of the tool you use. Choose a quality level that matches your needs.
Avoiding Common Mistakes
Two mistakes trip people up. First, converting from a JPG that was already converted from HEIC. This adds extra loss and can degrade quality noticeably. Always start from the original HEIC file. Second, assuming quality 100 means lossless. It does not. JPEG is always lossy. Quality 100 simply uses the least data removal. If you need lossless, use PNG.
The quality setting affects file size more than you might expect. Dropping from a higher setting to a lower one can cut the file size in half with almost no visible difference. Test a few settings with one photo to find your preferred balance.