Convert HEIC to JPG — what changes, what you lose, and how to do it without uploading your photos

What HEIC actually is — the container, the codec, and the compatibility wall

HEIC stands for High Efficiency Image Container. The container format is defined by the MPEG group; it uses HEVC (H.265) as the compression codec. That is the same codec used in 4K video, which means HEIC achieves roughly 50 % smaller file sizes than JPEG at equivalent perceptual quality. A 4 MB JPEG from your camera roll might be 1.8–2.2 MB as a HEIC file with no visible difference at normal viewing distances.

The compatibility problem is licensing. HEVC codec decoding requires hardware or software licensed by the patent pool. Apple licences it system-wide, so every iPhone and Mac reads HEIC without friction. Microsoft charges $0.99 for the HEVC Video Extensions on Windows — without it, File Explorer shows a thumbnail but no full preview, and many apps refuse to open the file at all. Android is fragmented: Google Photos handles HEIC on recent devices, but third-party editors and messaging apps often do not.

The practical result is that HEIC is excellent for storage on Apple hardware and essentially invisible everywhere else. The conversion need is real and common — the table below shows exactly where each platform stands.

What changes when you convert HEIC to JPEG

JPEG uses a different compression algorithm (DCT-based discrete cosine transform versus HEVC's prediction-and-transform pipeline). Converting always re-encodes the pixel data. At high quality settings — JPEG quality 90 or above — the visual difference is negligible for photographs. At quality 75 or below, JPEG compression artefacts become visible in gradients and fine detail. Most conversion tools default to quality 80–85, which is a reasonable trade-off between file size and sharpness.

File size goes up. A 1.9 MB HEIC typically becomes a 3.5–4.5 MB JPEG at quality 85, because JPEG is simply less efficient at compressing photographic content. That increase is the direct cost of compatibility.

EXIF metadata generally survives conversion if the tool copies it across explicitly. Camera model, lens, ISO, shutter speed, capture time, and GPS coordinates all travel inside the EXIF block. Some online converters strip metadata silently; local tools like the canvas-based converter built into this page copy the EXIF block from the source file to the output JPEG.

What does not survive HEIC to JPEG conversion

Live Photos are Apple-specific. A Live Photo is a short video loop (roughly 1.5 seconds before and after the still) bundled with the HEIC still image. JPEG has no container for video data. The conversion produces only the still frame; the motion component is discarded. If you want to keep the Live Photo loop, stay in HEIC or export the video component separately as an MP4 before converting.

Depth maps from Portrait Mode are stored as auxiliary image data inside the HEIC container — a second full-resolution greyscale image that encodes the depth per pixel. JPEG has no equivalent structure. The depth map is lost in conversion, which means Portrait Mode re-editing (adjusting background blur after the fact) is no longer possible on the converted file. The final rendered blur is baked into the pixels, but the editing data is gone.

HDR gain maps used in some newer iPhone captures store extended brightness data beyond standard dynamic range. JPEG is 8-bit per channel; it cannot carry the extra luminance information. The converter tone-maps the HDR content to the sRGB range, which may flatten highlights and shadows compared to viewing the HEIC on a device with an HDR display.

Burst sequences are a set of HEIC frames stored together in one container. JPEG has no multi-frame concept. The converter picks the key frame (the one the camera selected as best) and discards the rest. If you want to keep individual burst frames, export them separately from the Photos app before converting.

Five real scenarios where HEIC to JPEG conversion comes up

Sending photos from an iPhone to a colleague on Windows: AirDrop gives them a HEIC file their File Explorer cannot preview. Converting to JPEG before sending takes the problem off their desk entirely.

Uploading a product photo to an e-commerce platform: most platforms accept JPEG and PNG and reject or silently mangle HEIC. Converting locally at quality 90 gives you a known-good JPEG before the platform applies its own re-compression.

Submitting photos to a graphic designer who uses Windows-based tools: Photoshop and Illustrator on Windows require the Microsoft HEVC extension to open HEIC. Many designers do not have it. A JPEG arrives ready to work with.

Archiving family photos for long-term access: HEIC's 50 % size saving is attractive for storage, but JPEG has been readable by every device since the early 1990s and will continue to be. Converting a keepsake archive to JPEG ensures the files are accessible regardless of which platform or device handles them in ten or twenty years.

Using a photo as a website asset: Chrome and Firefox do not decode HEIC natively. A HEIC image referenced in an <img> tag renders a broken image icon in most browsers outside of Safari. Converting to JPEG — or to WebP for smaller files — is required for universal web display.

Four common errors when converting HEIC files

Converting at low JPEG quality to save space and then upscaling later. JPEG compression is irreversible. Once you encode at quality 60, the artefacts are baked in. Upscaling a low-quality JPEG makes it larger but does not recover the lost detail. Convert once at the highest quality you need, store that, and let the platform or use case determine further compression.

Expecting the converted JPEG to be smaller than the HEIC. HEIC is consistently smaller than JPEG at equivalent quality — that is the entire point of the format. Converting to JPEG and then complaining about file size growth is treating HEIC like a problem when it is the solution. If storage is the goal, keep the HEIC and convert only when compatibility requires it.

Assuming format conversion also strips metadata. Converting from HEIC to JPEG copies the EXIF block, including GPS coordinates, camera model, and capture time. If you want to share the converted photo without location data, run it through the GPS remover after converting. The conversion step alone does nothing to the metadata.

Using an online converter that requires uploading the file. Every major online HEIC converter sends your photo to a third-party server. For personal or sensitive photos — family shots, documents, anything with GPS coordinates — that means your file (and its embedded location data) reaches a server you do not control. Browser-based conversion using the local File API and Canvas API avoids this entirely.

How browser-based HEIC conversion works — and where it falls short

The browser decodes HEIC using a JavaScript HEIC decoder library (such as libheif compiled to WebAssembly). The decoded pixel data is drawn onto an HTML5 canvas and then exported as a JPEG using the canvas's built-in encoder at a specified quality setting. The whole pipeline runs in-tab. Nothing is sent over the network.

The limitation is processing speed. A WebAssembly HEIC decoder running in a single browser tab is slower than a native decoder. A 12 MP iPhone photo takes roughly 1–3 seconds to decode; a burst of twenty photos takes proportionally longer. For large batches, a native tool like ImageMagick or Apple's built-in export options in Photos will be faster. The browser tool is appropriate for converting individual files or small sets where privacy (no upload) matters more than throughput.

After converting, if you want to inspect or remove the EXIF block on the resulting JPEG, use the metadata viewer or the metadata batch stripper — both run in the same local, no-upload workflow.

How to batch-convert hundreds of iPhone photos without running out of memory

Dropping a single HEIC file into a converter is trivial. Dropping 600 photos from a two-week trip is where most tools silently fail. Browsers allocate memory from a shared tab pool; each decoded HEIC frame can temporarily occupy 30–80 MB of uncompressed pixel data before the JPEG encoder writes it back out. On a device with 8 GB of RAM and several other tabs open, queuing 300 files at once can push the tab over the browser's per-process ceiling and produce a silent crash or a stalled progress bar with no error message.

The practical fix is chunking. Rather than selecting your entire Camera Roll at once, work in batches of 50–80 files and let each batch finish before adding the next. Most browser-based converters that use a Web Worker pipeline process files sequentially rather than in parallel, so the peak memory footprint stays close to the cost of one decoded frame at a time rather than all frames simultaneously. If your converter shows a queue with per-file status indicators, that is a sign the implementation is doing this correctly.

File order matters for speed, not correctness. HEIC files from the same shooting session tend to share similar scene complexity, so interleaving portrait shots (large flat areas, low entropy) with landscape shots (high detail, higher entropy) can smooth out encoding time per file. In practice, the difference is small enough to ignore unless you are processing thousands of files. What matters more is closing other tabs before a large batch run — freeing 500–800 MB of RAM from a streaming video or a heavy web app is worth more than any queue optimisation. On iPhones using iOS 17 or later, Live Photos export as a HEIC plus a MOV sidecar; most converters only see the HEIC and silently drop the video component, so check your output folder if Live Photo motion matters to you.

Output file size, quality settings, and when keeping the original HEIC is the right call

A HEIC file from an iPhone 14 Pro at default camera settings typically lands between 3 MB and 6 MB for a 12-megapixel frame. Converting that file to JPEG at quality 85 — the default in most converters — usually produces a JPEG between 4 MB and 9 MB. That counter-intuitive size increase surprises people who expected JPEG to be smaller. It happens because HEIC uses HEVC compression, which is roughly twice as efficient as JPEG's DCT baseline at the same perceptual quality level. You are trading compression efficiency for universal compatibility, and the size penalty is real.

Quality sliders matter most in the 70–90 range. Below 70, JPEG block artefacts become visible on smooth gradients like skin tones and clear skies — exactly the subjects iPhone lenses are tuned to capture well. Above 90, file size grows steeply while perceived improvement becomes negligible on screen; quality 95 can produce a JPEG three times larger than quality 85 with differences only visible under pixel-level zoom. For sharing on social platforms that re-encode uploads anyway, quality 80 is a reasonable floor. For archival prints above A3 size, quality 90–92 is worth the extra megabytes.

There are three situations where keeping the original HEIC file alongside the JPEG is the right call. First, if you ever intend to re-edit the image in a colour-managed workflow — Lightroom, Capture One, or Apple's own Photos editor — the HEIC preserves the extended dynamic range data from HDR capture modes that JPEG cannot store. Second, if storage is not a constraint and you value the smaller on-device footprint while the files live on your phone, HEIC remains the better format for the camera roll itself. Third, if you converted at a quality setting below 85 for bandwidth reasons, the original HEIC is the only way to produce a higher-quality JPEG later without another generation of loss. Delete the HEIC only after you are confident the JPEG output meets your quality requirements for every intended use.

Privacy: why local conversion matters

iPhone photos routinely contain GPS coordinates accurate to 3–5 metres, the device serial number or model, the exact capture timestamp, and in some cases facial recognition data stored in private EXIF fields by Apple's Photos framework. Sending a HEIC file to an online converter means sending all of that to a server whose data retention policy you cannot verify. Local conversion in a browser tab means none of that data leaves your device at any point in the workflow.