Add your HDR file
Drop one or more .hdr files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Converting a .hdr image to .webp re-encodes the pixels for a different balance of size, quality, and support. Free, private, and validated — the file never leaves your browser.
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.Converting a .hdr image to .webp re-encodes the pixels for a different balance of size, quality, and support. An .hdr file is a Radiance RGBE image, the original high-dynamic-range raster format. Each pixel stores three 8-bit mantissas and one shared 8-bit exponent, so 32 bits per pixel cover a luminance range no ordinary 8-bit format can express. It is still the everyday container for the HDRI environment maps used to light 3D scenes.
A .webp file is Google's web-oriented image format, offering both lossy and lossless compression plus alpha and animation in one container. At equivalent visual quality, .webp files typically undercut JPEG by 25-35 percent, which is why CDNs and site optimizers convert to it aggressively. For this route the practical draw is smaller than JPEG for photos and usually smaller than PNG for graphics and one format covers lossy, lossless, alpha, and animation — balanced against mandatory 4:2:0 subsampling in lossy mode caps color fidelity below high-quality JPEG or AVIF, which is worth knowing before you commit a large batch.
The practical trigger for this conversion is usually a mismatch: with .hdr, only about 1 percent precision per channel, and the shared exponent hurts saturated colours. Switching to .webp buys you smaller than JPEG for photos and usually smaller than PNG for graphics, which is why it is the better fit for serving photos and graphics on websites where bandwidth and Core Web Vitals matter. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
| Aspect | Radiance HDR image (.hdr) | WebP image (.webp) |
|---|---|---|
| Format type | Lossy — discards detail it judges invisible to shrink files | Lossy — discards detail it judges invisible to shrink files |
| How it stores data | rGBE encoding: three 8-bit mantissas plus one shared 8-bit exponent, 32 bits per pixel | lossy mode encodes VP8 intra frames with block prediction; lossless mode uses its own dedicated coding with spatial predictors and color transforms |
| Strongest at | hDRI environment maps and sky domes for image-based lighting in Blender, Unreal, Unity and V-Ray | serving photos and graphics on websites where bandwidth and Core Web Vitals matter |
| Weak spot | only about 1 percent precision per channel, and the shared exponent hurts saturated colours | mandatory 4:2:0 subsampling in lossy mode caps color fidelity below high-quality JPEG or AVIF |
| Metadata | the text header carries EXPOSURE, GAMMA, PRIMARIES, SOFTWARE and free-form comment lines. There is no EXIF, XMP or ICC profile block, and this converter's raster outputs do not carry the header lines across | eXIF and XMP travel in dedicated RIFF chunks and ICC profiles are supported, though a fair amount of conversion software strips metadata by default when writing WebP |
Drop one or more .hdr files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Select .webp in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if WEBP is selectable, the route is real and validated.
Press Convert. Decoding and re-encoding happen on your device using the browser's native image pipeline and hand-tuned encoders.
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid WEBP file. Outputs keep the original filename with the .webp extension.
A second lossy step always costs a little, because hdr is lossy-oriented and webp is lossy-oriented and each encoder discards detail differently (generation loss). At the default quality the difference is rarely visible; avoid repeated round-trips between .hdr and .webp.
Yes — the .hdr file is processed inside your browser tab and never uploaded. Decoding and re-encoding happen on your device using the browser's native image pipeline and hand-tuned encoders. Close the tab and the file is gone from memory.
Chrome, Edge, Firefox, and Safari (since version 14 in 2020) all decode WebP natively, as do Android and current versions of Windows and macOS system viewers. Older tools from before roughly 2020 — legacy Photoshop releases, older email clients, many kiosk printers — commonly fail on it, so JPEG or PNG remains the safer handoff format outside the browser.
It depends on the content: lossy mode encodes VP8 intra frames with block prediction; lossless mode uses its own dedicated coding with spatial predictors and color transforms. Convert one representative file first and compare before batch-processing a large set.
In .hdr, the text header carries EXPOSURE, GAMMA, PRIMARIES, SOFTWARE and free-form comment lines. There is no EXIF, XMP or ICC profile block, and this converter's raster outputs do not carry the header lines across. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.