How to Convert HEIC to JPG to a Specific File Size

Why Convert HEIC to JPG With a Target File Size?

Many websites and online systems place limits on the size of image files they accept. A standard HEIC-to-JPG conversion may create a compatible JPG, but the resulting file can still be larger than the limit you need.

Target File Size mode combines these tasks into one workflow:

• convert the HEIC or HEIF image to JPG;
• attempt to keep the resulting JPG at or below your selected size;
• reduce JPEG quality when necessary; and
• reduce image dimensions when a very small target cannot be reached through quality adjustment alone.

This can save you from converting an image first and then opening a separate image compressor. For basic conversion steps without size limits, see our guide on how to convert HEIC to JPG.

Always check the requirements of the website or service where you plan to use the image. A file-size limit may be accompanied by requirements for dimensions, aspect ratio, image content, or format.

What Happens When You Choose 20 KB?

20 KB is a very small target for a photo, especially when the original HEIC image has a high resolution.

The converter first attempts to preserve image dimensions while adjusting JPEG compression. If the JPG is still too large, the converter may reduce the image dimensions to attempt to meet the selected limit.

As a result, a 20 KB output may have noticeably lower image quality or smaller dimensions than the original photo.

Use a target this small only when you actually need a very small image file.

A 20 KB target is not a guarantee that every source image can be reduced to 20 KB while remaining usable. If the requested target cannot be reached within the converter's safe processing limits, the result should be identified accordingly.

50 KB vs 100 KB vs 200 KB — Which Should You Choose?

There is no single best file size for every image.

If a website specifies a maximum image size, use that requirement to choose your target rather than selecting the smallest preset automatically.

Target File Size vs JPG Quality

The converter provides two different ways to control JPG output.

JPG Quality is useful when you want direct control over JPEG quality.

Target File Size is useful when staying under a particular file-size limit is more important.

When Quality is selected, you choose the JPEG quality level.

When Target File Size is selected, the converter automatically adjusts compression and, when necessary, dimensions while attempting to keep the JPG within your selected maximum size.

Both options produce JPG files. They simply give you different ways to control the result.

Does the Converter Produce Exactly 50 KB or 100 KB?

No. A target is treated as a maximum-size goal rather than an instruction to produce an exact byte count.

For example, if you select 100 KB, a result of 96 KB can satisfy the target. There is no benefit in making the file larger merely to reach exactly 100 KB.

Actual JPEG size depends on factors such as image dimensions, visual detail, texture, noise, and the amount of compression required.

The goal is to produce a practical JPG at or below the selected maximum whenever possible, not to force every output to have exactly the same size.

Can I Use a Custom Target Size?

Yes. If one of the standard presets does not match your requirement, choose Custom and enter the file-size target you need.

For example, if a website accepts images up to 75 KB, you can enter a 75 KB target instead of choosing 50 KB or 100 KB.

The custom target applies to each image individually.

What Happens With Multiple Images?

Target File Size also works with batch conversion. If you regularly process multiple photos, see our guide on how to bulk convert HEIC to JPG for a detailed explanation of batch processing.

If you select multiple HEIC or HEIF photos and choose a 50 KB target, the converter attempts to keep each resulting JPG at or below 50 KB independently.

For example:

• Photo 1 → 47 KB
• Photo 2 → 49 KB
• Photo 3 → 43 KB

The target does not mean that the entire batch must fit inside 50 KB.

Each image is optimized separately because different photos compress differently.

Why Two Photos Can Produce Different JPG Sizes

Two images with the same dimensions do not necessarily produce JPG files of the same size.

A photo containing fine detail, texture, foliage, hair, text, or image noise can require more data than a simple image containing large smooth areas.

That is why the converter evaluates each image independently instead of assuming that one compression setting will produce the same file size for every photo.

Private Browser-Based Processing

HEICJPGOnline performs the image conversion locally in your web browser.

Your selected HEIC or HEIF photos are not uploaded to our servers for conversion. The browser decodes the image and creates the JPG on your device.

This client-side approach is particularly useful when working with personal photos because the selected image files do not need to be sent to a remote conversion server.