Why HEIC files get so big
HEIC is already an efficient format, which is exactly why people are surprised when their photos still eat gigabytes.
A modern phone camera shoots 12 megapixels or more. The photo we measured for this page is 4000 by 3000 pixels and weighs 1.38 MB straight off the camera — and that is the format doing its job well.
A single HEIC is also rarely just one picture. The container can carry a depth map, an HDR gain map, the short video half of a Live Photo, and a full EXIF block with GPS coordinates, all inside the same file.
Multiply that by a full camera roll and the storage problem becomes obvious.
The other surprise comes when people try to fix it by converting. Here is the same photo written six different ways.
Converting that HEIC to a high-quality JPG produced a larger file: 1.68 MB at quality 90. Saving it as PNG produced 13.7 MB, ten times the original. Only a deliberate compression step actually reduces HEIC file size.
What does a HEIC compressor actually output?
This is the question every competing page avoids, so let us answer it plainly.
No browser can create a HEIC file. HEIC uses HEVC compression, which is patent-encumbered, so a HEIC compressor that runs in your browser must output a different format — usually WebP or JPG.
Your browser can read a HEIC perfectly well. Writing one is the part that does not exist, and no amount of clever code works around a licensing problem.
That leaves every HEIC compressor with two honest options.
The first is to upload your photos to a server, compress them there with a licensed encoder, and send back a real HEIC. It works, but your private photos leave your device.
The second is to compress on your device and hand back WebP or JPG. Nothing is uploaded, and the file you get opens on more devices than the HEIC did. We picked this one.
What we will not do is take the second route and describe it as the first. If you find a tool that compresses HEIC in your browser and never mentions the output format, download a file and look at its extension.
For the whole story on why HEIC encoding is off the table in a browser, see our guide on why browsers cannot create HEIC files.
How to compress HEIC files in 3 steps
1. Add your photos
Drag a folder onto the drop zone, paste from the clipboard, or click to browse. Files never leave your device, so large batches start immediately with no upload wait.
2. Choose how you want to compress HEIC
Quality mode gives you a slider. Target size mode lets you name a budget and does the searching for you.
Pick WebP for the smallest result, or JPG when something downstream refuses to accept a .webp.
3. Download
Save files one at a time, or take the whole batch as a single .zip. Each row shows the before and after size, so you can see exactly what you gained.
Choosing a quality level
Quality is the dial that decides everything when you compress HEIC photos. Here is what it did to our test photo, measured end to end through this exact tool.
| Quality | Result | vs the original HEIC |
|---|---|---|
| 90 | 1.68 MB | 22% bigger |
| 85 | 1.27 MB | 8% smaller |
| 80 | 1.04 MB | 24% smaller |
| 75 | 0.86 MB | 37% smaller |
| 60 | 0.56 MB | 59% smaller |
| 40 | 0.37 MB | 73% smaller |
The line to notice is the top one. High quality settings do not shrink a HEIC, they inflate it, because HEVC is simply a more efficient compressor than JPEG.
WebP does better across the board. At quality 82 the same photo came out 66% smaller, a result JPEG could not match until quality 60. That is why WebP is the default here, and why our HEIC to WebP converter exists as well.
For everyday photos, 75 to 85 is the range where nobody can see the difference. Below 60 you will start to notice softness in fine detail.
These numbers come from one 12 megapixel photo. Treat them as a guide to the shape of the curve, not a promise about your own library.
WebP or JPG: which output should you pick?
Since a browser cannot hand back a HEIC, the real choice is which replacement you want.
| WebP | JPG | |
|---|---|---|
| Size on our test photo | 0.47 MB at quality 82 | 0.86 MB at quality 75 |
| Browser support | Every browser since 2020 | Everything ever made |
| Older apps and devices | Sometimes refused | Always accepted |
| Best for | Websites, storage, messaging | Printing, uploads, anything picky |
WebP is the default because it wins on size by a wide margin. Compressing HEIC to WebP gave us a 66% reduction where JPEG needed to drop to quality 60 to get close.
Switch to JPG when something downstream is fussy: an older printing service, a government upload form, a desktop app that has not been updated in a decade. The file will be larger, but it will never be rejected for its format.
If you want the conversion without the compression step, our HEIC to JPG converter and HEIC to PNG converter handle those directly.
Compress HEIC to an exact file size
Sometimes the requirement is not “smaller”, it is a hard number: a 25 MB email limit, a 2 MB forum cap, a 200 KB upload field. A quality slider alone will not reduce HEIC file size to a specific target without a lot of guessing.
Target size mode handles that. Name your budget and the tool searches for the highest quality that still fits underneath it.
The search halves the remaining quality range on every attempt and stops as soon as it lands just under your budget, which on our test file took between two and five encodes.
When even the lowest quality overshoots, the photo has too many pixels for the budget you set. The tool then steps the dimensions down and searches again, and it tells you it did rather than quietly handing back a smaller picture.
Our test file shows where that boundary sits: at full 4000 by 3000 resolution the smallest usable JPEG was around 0.30 MB. To get under 200 KB it had to come down to 1920 pixels wide.
Compressing versus resizing: which do you need?
These two get mixed up constantly, and they solve different problems.
| Compress | Resize | |
|---|---|---|
| What changes | Bytes per pixel | Number of pixels |
| Dimensions | Unchanged | Smaller |
| Best for | Email, uploads, storage | Web pages, thumbnails, avatars |
| Detail when zoomed | Slightly softer | Fewer pixels to zoom into |
Compress when the picture needs to stay full size and the file is the problem. Reach for our HEIC resizer when the dimensions themselves are wrong.
For the biggest reduction, do both. Our measurements showed a 1920 pixel wide copy at quality 75 landing at 0.20 MB, roughly a seventh of the original.
When you should not compress a HEIC
The decision to compress HEIC files is lossy and permanent. There are cases where it is the wrong move.
Keep the original when the photo is going to be printed large. Fine detail that looks fine on a phone screen shows up as mush at A3.
Keep it when you still plan to edit. Every round of lossy compression bakes in the last one, so heavy edits on an already-compressed file compound the damage.
Keep it when the photo is the archive copy. Compress a duplicate for sharing and leave the original alone.
And keep it when the file is already small. A 400 KB HEIC has very little left to give, and pushing it through another lossy encoder mostly trades quality for nothing.
Why we do not upload your photos
Most online tools that compress HEIC take your photos, process them on a server, and promise to delete them within a few hours. You have to take that on faith.
There is a simple test you can run on any tool that claims to work locally. Load the page, turn off your Wi-Fi, then compress a file. Ours keeps working. Anything that uploads cannot even start.
That same architecture is why there are no file-size caps here and no queue. Your device is doing the work, so the only limit is your own hardware.
Two claims in this category deserve a closer look, because both appear on competing pages. One tool states that processing happens in your browser and, further down the same page, that files are stored on its servers for two hours. Another advertises lossless compression that also reduces file size — but lossless compression preserves every pixel, and a photo that is already HEVC-compressed has almost nothing left to squeeze out losslessly.
If a compressor’s own page contradicts itself, that is worth more than any privacy badge on it.
Your metadata is a separate question. Compressed output drops the EXIF block, including GPS coordinates, which is usually what you want before sharing. If you want to see what is in your photos first, our HEIC EXIF viewer reads it locally too.
The bottom line
A browser-based HEIC compressor cannot give you back a HEIC, and any tool that implies otherwise is either uploading your photos or not telling you what it produced.
What it can do is make the file genuinely smaller while keeping it on your device. On our test photo that meant 66% off at WebP quality 82, with nothing crossing the network.
Pick quality mode when you just want smaller files, and target mode when a form is enforcing a hard limit. Stay between 75 and 85 for anything you care about, and keep the original whenever the photo is destined for print, editing, or an archive.
Everything above was measured through this page’s own tool, on one 12 megapixel photo. Run your own file through it and the numbers on screen will tell you exactly what you saved.