How to convert HEIC to WebP on iPhone
Two modern, efficient formats — and the only real difference that matters is who can open them. HEIC is the better codec. WebP is the one the web actually reads.
Two good formats, one compatibility gap
HEIC is a HEIF container holding an HEVC (H.265) encoded image — Apple's camera default since iOS 11. Technically it is the stronger format: excellent compression, 10-bit colour, room for depth maps and HDR gain maps.
WebP is Google's format, based on VP8 intra-frame coding, with an alpha channel and a separate lossless mode. It is slightly less efficient than HEVC in most comparisons.
But HEVC is patent-encumbered, and that killed HEIC on the web. No mainstream browser will display a HEIC. WebP, by contrast, is royalty-free and supported by every current browser. If your photo is going onto a website, into a web app, or anywhere a browser has to render it, HEIC is simply not an option and WebP is the natural target.
Why almost no iPhone app can do this: Apple's ImageIO framework decodes WebP but ships no WebP encoder. Apps built purely on Apple's frameworks can therefore read WebP and never write it. Convexy bundles Google's libwebp and encodes through that. This is the same reason you keep finding converters that take WebP in and refuse to hand it back.
What the conversion costs
- It is a re-encode. The HEIC is decoded to pixels and compressed again by a different lossy codec. Generation loss is real, though at a sensible quality setting it is invisible on a photograph.
- Expect the file to grow a little. HEVC generally beats VP8, so the WebP will often be somewhat larger than the HEIC at matched quality. You are paying a modest size premium for universal browser support — a good trade for web use, a pointless one for local storage.
- 10-bit becomes 8-bit. Standard WebP is 8-bit. On most photos you will not see it; on a smooth gradient you might notice faint banding.
- Extras do not survive. Depth maps, Live Photo motion and HDR gain maps have nowhere to live in a WebP.
The quality slider, and its one surprise
Below 100% you get lossy VP8 at that quality factor, with the alpha channel (if any) still stored losslessly. At 100% Convexy switches libwebp into its lossless encoder — a pixel-exact copy of what the HEIC decoded to. That is genuinely lossless from this point forward, but the file will be large, and it still cannot undo the lossy compression the HEIC applied when your camera wrote it. For web delivery, a lossy setting is almost always the correct choice.
If you have a choice, encode from the least-compressed source you have. HEIC → WebP stacks two lossy codecs. If the image also exists as a RAW/DNG or a PNG, convert from that instead — one lossy generation always beats two.
When AVIF is the better target
If your audience is on current browsers, consider AVIF instead. It is AV1-based, royalty-free, and compresses better than WebP — closer to HEIC's efficiency without the patent problem. Browser support is now broad but not quite as universal as WebP's. WebP is the safe default; AVIF is the better codec.
Nothing leaves the phone
iOS decodes the HEIC, libwebp encodes the WebP, and both happen on your device. There is no upload, no account, no server. Metadata — including the GPS coordinates your camera wrote into the HEIC — is stripped by default, which is the right default for anything you are about to publish on the web.
How to do it
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Pick the HEIC
Tap Browse files or pick from Photos. Selecting several at once sends them to the batch screen, which is what you want when preparing a set of images for a site.
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Choose WebP
WebP appears among the formats a HEIC can become. Convexy writes it with the bundled libwebp encoder, because Apple's frameworks cannot.
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Set the quality
For web use, a lossy setting below 100% is right — that is the whole point of WebP. Push it to 100% only if you specifically want libwebp's lossless mode.
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Resize for the web
An iPhone photo is far larger than any web layout needs. Setting a maximum dimension in Options will cut more bytes than any codec choice.
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Convert, then save or share
Compare the sizes on the result screen, then save to Files or push the image straight into your publishing tool from the share sheet.
Common questions
Why convert HEIC to WebP instead of JPG?
Because WebP is meaningfully smaller than JPG at the same quality — typically 25–35% — while being just as readable by every current browser. If the destination is a web page, WebP is the better choice. If the destination is an old desktop application or a print shop, JPG is the safer one.
Will the WebP be smaller than the HEIC?
Probably not, and that surprises people. HEVC is generally a more efficient codec than VP8, so at matched quality the WebP is often a bit larger. You convert for compatibility, not for size. HEIC remains the better format for storing photos on your own device.
Can browsers display HEIC yet?
No mainstream browser renders HEIC. The format depends on HEVC, which is patent-licensed, and browser vendors have not shipped support. That is precisely why this conversion exists: an iPhone photo cannot be put on the web as-is, no matter how good the codec is.
Does converting to WebP lose quality?
At any lossy setting, yes — it is a second lossy encode after the camera's HEIC encode. At a normal quality setting the difference is not visible on a photograph. At 100% Convexy uses libwebp's lossless mode, which adds no further loss but produces a much bigger file and cannot recover what the HEIC already discarded.
Does it keep the GPS location from the photo?
Not unless you ask it to. Convexy strips EXIF, GPS, IPTC and TIFF metadata by default. Since HEIC-to-WebP is usually a prelude to publishing an image on the internet, that default is deliberate — intact EXIF in a published photo can reveal exactly where it was taken. Turn the toggle off in Options if you genuinely need the tags kept.