HEIC to JPG Without Losing Quality: What You Can Control

You cannot convert HEIC to JPG with zero loss: both formats use lossy compression, so the conversion decodes the photo and compresses it a second time. What you can control is how much that second step costs. Convert once, straight from the HEIC original; use a quality of 90 or higher; keep the original size; and keep the HEIC file. Below are measurements for each quality setting, and the reasons behind each tip.

Why some loss cannot be avoided

• HEIC is already lossy. HEIF files can hold lossy or lossless images, according to the HEIF technical summary, but our camera photos were clearly stored with loss: three of our 12 MP test photos were 0.9–1.7 MB as HEIC, while the same decoded pixels stored losslessly as PNG took 12.3–16.7 MB.
• JPG is lossy too. MDN’s image format guide lists JPEG compression as “Lossy; based on the discrete cosine transform”.
• So the conversion adds a second loss. Lost detail from the HEIC step cannot come back, and the JPG step adds a little more. The quality setting decides how much.

What the quality setting does: measured

We converted four real phone photos (about 12 megapixels each) on heicly in desktop Chromium and saved the JPG at five quality settings. To see how close each JPG is to the decoded photo, we compared it pixel by pixel with a lossless PNG of the same decode and calculated PSNR (peak signal-to-noise ratio, in dB). Higher PSNR means closer to the decoded photo. It measures only the JPG step; the HEIC’s own loss is not included.

File size (MB)

Phone (from the photo’s Exif)	100	95	90 (default)	80	70
iPhone 7	5.48	2.21	1.49	0.95	0.72
iPhone 12 Pro	7.25	3.53	2.55	1.75	1.37
Samsung SM-A326B	5.64	2.50	1.70	1.08	0.80
Samsung SM-S906U	4.29	2.12	1.30	0.66	0.41

PSNR against the decoded photo (dB, higher is closer)

Phone	100	95	90	80	70
iPhone 7	57.2	48.1	45.9	43.6	42.1
iPhone 12 Pro	56.9	47.1	44.3	41.2	39.4
Samsung SM-A326B	57.4	47.5	45.4	43.0	41.6
Samsung SM-S906U	58.9	49.5	46.8	44.1	42.7

1 MB = 1,000,000 bytes. The JPGs include the date taken and camera details.

What this shows:

• Moving from 90 to 95 made the files 1.4–1.6 times larger; moving to 100 made them 2.8–3.7 times larger.
• Going down from 90 to 80 saved 31–49% of the size, and PSNR dropped by 2.4–3.1 dB.
• Even quality 100 is not lossless: PSNR stayed below 60 dB, and the files were 37–44% of the size of the lossless PNG.

PSNR is a numeric measure, not a verdict on what you will see. Whether a difference is visible depends on the photo, your screen and how far you zoom in, so compare two settings on one of your own photos before converting a whole album.

Tip 1: Convert once, from the HEIC original

Each time a JPG is opened and saved as JPG again, it is compressed again. We re-saved each quality-90 JPG four more times at quality 90 with the same browser encoder. PSNR fell by 0.01–0.33 dB over those four saves: small with identical settings, but it only goes one way. We did not test other apps or other settings.

Raising the quality later does not undo earlier loss. When we re-saved quality-70 JPGs at quality 100, PSNR stayed at 39.3–42.7 dB, slightly lower than before, while the files grew 3.6–4.8 times.

In heicly, moving the quality slider re-encodes from the decoded photo held in memory, not from the previous JPG, so trying several values on one photo does not stack loss.

Tip 2: Do not detour through PNG

HEIC → PNG → JPG does not give a better JPG. The PNG step is lossless, so it neither adds nor recovers detail; the final JPG still goes through the same single lossy step. The detour does cost something: heicly’s PNG files carry no date taken or camera details, so a JPG made from them loses that information, and the PNG in between was 6.6–9 times the size of the JPG in our test. See HEIC to JPG or PNG for when PNG is the right final format.

Tip 3: Choose a quality to match the job

heicly’s slider runs from 1 to 100 and starts at 90. Use the tables above to decide: 95 or 100 keeps the JPG closer to the decoded photo at a much larger size; 80 or lower saves space with more compression loss. For a batch of photos, use “Quality for this batch”. It applies to files that are still waiting; files that have already finished keep their quality, and the page tells you to select them again if you want the new value.

Tip 4: Keep the original size

“Output size” starts at “Original size”. The options “Long edge 2560 px”, “Long edge 1920 px” and “Long edge 1280 px” make smaller images with fewer pixels, which is useful for sharing but not for keeping full detail.

There is one limit you cannot switch off: images larger than 16,777,216 pixels are resized proportionally to fit the browser’s limits. In our test, a 48 MP iPhone 16 Pro photo (8064 × 6048) came out at 4729 × 3547, and the page added “(resized to fit your browser’s limits)” next to the size. If you need every pixel of a 48 MP photo, keep the HEIC original.

Tip 5: Keep the HEIC original

The HEIC is the best copy you have. Keep it, and make JPG copies when you need to share, upload or print.

Convert in your browser

The converter below runs on this page, and your photos are not uploaded.

1. Drag a HEIC file into the box, or click “Choose Files”.
2. Move the quality slider to the value you want. It starts at 90, and the download updates with the new size.
3. Download the JPG. For many photos, adjust “Quality for this batch” for the files still waiting; the next batch you add starts from the value you chose. Download the batch as one ZIP.

Sources

Checked on 31 October 2026: the HEIF technical summary from Nokia and MDN’s image file type and format guide. File sizes and PSNR are our own measurements with heicly in desktop Chromium.

Summary

• Some loss is unavoidable, because HEIC and JPG are both lossy.
• Convert once from the HEIC at quality 90 or higher, at the original size.
• Do not re-save JPGs or detour through PNG, and keep the HEIC original.

New to the formats? Read HEIC vs JPG. Converting many photos? Use batch HEIC to JPG.