Which Video Formats Support Transparency (Alpha Channel)?

Q: Do Chrome, Firefox, Edge, and Safari play transparent WebM?

Chrome, Firefox, and Edge: yes, alpha kept (tested). Safari macOS: plays but not transparent (grey background) per WebKit bug #275908 — docs only, not tested by us. Safari iOS WebM alpha: not verified — official sources do not spell out iOS behavior; WebKit bug #275908 is reference only. See the WebM × Safari guide.

Four formats matter for transparent video: WebM VP9 with alpha, HEVC with alpha, ProRes 4444 MOV, and PNG. Which one to use depends on where the video will play. Everyday H.264 MP4 has no alpha channel.

Chrome, Firefox, Edge, OBS: WebM VP9 with alpha keeps transparency (tested on Linux, 2026-09-24).
Safari on macOS: plays WebM but shows a grey background instead of transparency, per WebKit bug #275908 (not tested by us). Safari on iOS with WebM alpha is not verified — official sources do not spell out iOS behavior.
Safari (iOS 13+ / macOS Catalina+): Apple documents HEVC Video with Alpha (WWDC19 session 506).
Editing and OBS: ProRes 4444 MOV keeps alpha in OBS (tested). Editor support comes from vendor docs, not our own import tests.
H.264 MP4: plays everywhere we tested, but transparent areas render black (tested).

Each cell in the matrix below is marked tested, from official docs, or untested.

Compatibility matrix

Tested 2026-09-24 on Linux; see How we tested.

Legend

Legend for matrix cell symbols
Symbol	Meaning
✓ Keeps alpha	Local visual test: transparent area showed the magenta page/canvas background
✗ Black bg	Local visual test: file played; former transparent area rendered black
✗ Won't play	Local demux/play failure
N/A · ✓ img	Not a <video> format for that target; single-frame <img> kept alpha (tested)
Docs: grey bg	Official docs: plays but grey background rather than transparent — not tested by us
Docs: supported	Official documentation claims support — not tested by us
Docs: ProRes alpha	Official docs: ProRes import/export + only 4444/XQ carry alpha (Apple) — not tested by us
Docs: Decode Yes	Official codec list: Decode Yes (and Alpha Exports=4444 where noted) — not tested by us
Docs: PNG import	Official docs list PNG import (no alpha-preserved sentence) — not tested by us
Docs: PNG seq	Official docs: PNG import; stills as sequence — not tested by us
Docs: PNG stills	Official docs: PNG stills supported — not tested by us
Untested	No local test and no usable official sentence for this cell
Not verified	Weak / incomplete docs — we do not assert a result

Table A — Browsers: format × Chrome, Firefox, Edge, Safari (macOS), Safari (iOS). Non-tested cells cite official sources in footnotes.
Format	Chrome	Firefox	Edge	Safari macOS	Safari iOS
WebM VP9 with alpha	✓ Keeps alpha	✓ Keeps alpha	✓ Keeps alpha	Docs: grey bg^w1	Not verified^w2
HEVC with alpha	Untested^h1	Untested^h1	Untested^h1	Docs: supported^h2	Docs: supported^h3
ProRes 4444 MOV	✗ Won't play	✗ Won't play	✗ Won't play	Untested	Untested
MP4 H.264 (no alpha)	✗ Black bg	✗ Black bg	✗ Black bg	Untested	Untested
PNG sequence	N/A · ✓ img	N/A · ✓ img	N/A · ✓ img	Untested	Untested

Table B — Editing & streaming: format × OBS, Premiere Pro, DaVinci Resolve, After Effects, Final Cut Pro. Non-tested cells cite official sources in footnotes.
Format	OBS Studio	Adobe Premiere Pro	DaVinci Resolve	Adobe After Effects	Final Cut Pro
WebM VP9 with alpha	✓ Keeps alpha	Untested	Untested	Untested	Untested
HEVC with alpha	Untested	Untested	Untested	Untested	Untested
ProRes 4444 MOV	✓ Keeps alpha	Docs: ProRes alpha^p1	Docs: Decode Yes^p2	Docs: ProRes alpha^p3	Docs: ProRes alpha^p4
MP4 H.264 (no alpha)	✗ Black bg	Untested	Untested	Untested	Untested
PNG sequence	Untested	Docs: PNG importⁿ¹	Docs: Decode Yesⁿ²	Docs: PNG seqⁿ³	Docs: PNG stillsⁿ⁴

Cell counts: 15 tested · 11 official docs · 24 untested (50 cells; Safari iOS × WebM shown as Not verified).

w1. WebKit Safari 14.1 WebM support (VP8/VP9 on macOS). WebKit bug #275908: “VP9 with transparency plays back incorrectly… grey background rather than transparent” (status NEW). Not tested by us.
w2. WebKit bug #275908 is reference only — it does not explicitly cover iOS. Apple’s Safari 14.1 WebM write-up emphasizes macOS. Official sources do not spell out iOS WebM-with-alpha behavior; we have not tested iOS. This cell is Not verified, not a Docs claim.
h1. Could not produce a true HEVC-with-alpha file on Linux (libx265 drops alpha). Local browser cells left untested.
h2. WWDC19 session 506: “HEVC video with Alpha is supported by Safari in iOS 13 and macOS Catalina.” Also AVFoundation HEVC-with-alpha, Interoperability Profile PDF.
h3. Same WWDC19 506 quote for iOS 13.
p1. Adobe Premiere supported formats (Apple ProRes import). Apple ProRes 102207: only 4444 / 4444 XQ support alpha. Not an import-keeps-alpha lab test.
p2. DaVinci Resolve 20 Supported Codec List PDF: Apple ProRes · mov/mkv · Alpha Exports: 4444 · Decode: Yes.
p3. After Effects supported formats (Apple ProRes import/export) + Apple 102207. AE page does not spell out “4444 alpha preserved on import.”
p4. Final Cut supported media (Apple ProRes all versions); Apple 102207; Use alpha channels; Preserve alpha → 4444/XQ.
n1. Premiere supported formats — PNG listed; no official sentence that sequence alpha is preserved.
n2. Resolve 20 codec list: png Decode/Encode Yes (RGB 8/16-bit).
n3. AE supported formats: Portable Network Graphics (.png); “import files of any still image format as a sequence.”
n4. Final Cut supported media: Still-image formats — PNG.

Need a file now?

ExportAlpha writes WebM VP9 alpha and ProRes 4444 MOV in the browser — not HEVC-with-alpha, not MP4 alpha.

Try it See pricing

Scenario recommendations

Web browsers (Chrome / Firefox / Edge)

Use: WebM VP9 with alpha (yuva420p).
Why: ✓ Tested — alpha kept in Chrome 151, Firefox 153, and Edge 153.0.4234.48 on Debian 13 (magenta background showed through).
Don't use for alpha: Everyday H.264 MP4 — ✗ Tested; plays, transparent area black.
Unverified here: macOS/Windows builds of the same browsers (Linux-only test caveats).
More: How to make a transparent WebM.

Safari — macOS

WebM alpha: Docs only — plays, but not transparent (grey background) per WebKit bug #275908. Not tested by us.
For real transparency: HEVC Video with Alpha — Apple docs (WWDC19 506): supported by Safari on macOS Catalina. We could not encode a true HEVC-alpha file on Linux, so we did not play-test it.
ProRes 4444 in Safari <video>: Untested.
Deep dive: Why is my transparent WebM black in Safari?.

Safari — iOS

WebM alpha: Not verified. Official sources do not spell out iOS WebM-with-alpha behavior; WebKit bug #275908 is reference only. Do not assert play-or-grey on iOS from this matrix.
HEVC Video with Alpha: Docs — supported from iOS 13 (WWDC19 506). Untested by us (no true HEVC-alpha encode on Linux).
ExportAlpha does not export HEVC-with-alpha; encode that file elsewhere if Safari must show holes.

OBS / streaming

Use: WebM VP9 with alpha via Media Source — ✓ Tested (OBS 30.2.3; alpha kept over magenta Color Source).
Also works in our OBS test: ProRes 4444 MOV — ✓ Tested (keeps alpha).
MP4 H.264: ✗ Tested — plays; no alpha (black in former transparent area).
HEVC-with-alpha / PNG sequence in OBS: Untested.
Guides: Transparent video overlay in OBS · OBS Stinger WebM.

Editing software

Editor support claims vs unverified gaps
App	What the table supports saying	What stays unverified
Premiere Pro	Docs: imports Apple ProRes (Adobe); ProRes 4444 carries alpha (Apple 102207).	We did not test “import keeps alpha.” WebM VP9 alpha: Untested.
DaVinci Resolve	Docs: ProRes Alpha Exports=4444, Decode Yes (codec list PDF).	No local import test. WebM VP9 alpha: Untested.
After Effects	Docs: ProRes import/export (Adobe) + only 4444/XQ carry alpha (Apple).	No local “alpha preserved” test. WebM: Untested.
Final Cut Pro	Docs: imports all ProRes versions; Apple says choose 4444/XQ to preserve alpha; FCP alpha compositing docs.	Stronger docs than Premiere/AE; still not our lab test. WebM: Untested.

Practical pick from the table: ProRes 4444 MOV for editorial handoff (docs + OBS tested). WebM×editors = untested — do not claim editor WebM alpha support here.

What about MP4?

Everyday H.264 MP4 was our no-alpha control. On Chrome, Firefox, Edge, and OBS it plays, and the transparent area renders black — ✗ Tested (no alpha). Safari × MP4 and all editor × MP4 cells are Untested (the control file itself has no alpha per ffprobe yuv420p).

An extra encode attempting yuva420p + libx264 still produced yuv420p with no alpha (builder encode log).

Full explainer: Does MP4 support a transparent background?

What about PNG / PNG sequences?

PNG is not an HTML5 <video> format — browser <video> cells are N/A.
A single-frame PNG via <img> kept alpha in Chrome, Firefox, and Edge (✓ Tested).
Safari / OBS × PNG sequence: Untested.
Editors: Premiere/AE/Resolve/FCP docs confirm PNG import (and AE: stills as sequence). Premiere’s official page does not give a sentence that sequence alpha is preserved — we do not claim that.
ExportAlpha exports transparent PNG stills, not a video PNG sequence.

How we tested

Test environment details
Item	Detail
Date	2026-09-24 (Asia/Shanghai)
OS	Debian GNU/Linux 13 (trixie)
Browsers	Chrome 151.0.7922.169 · Firefox 153.0 (Playwright) · Edge 153.0.4234.48
OBS	30.2.3.1-3 (X11)
ffmpeg	7.1.5-0+deb13u1
Clips	ffmpeg-generated 4-second synthetic transparent clips (cyan circle on transparent), not ExportAlpha tool-pipeline exports
Encodes (pix_fmt / codec)	WebM VP9: `libvpx-vp9` `yuva420p` · HEVC-with-alpha: Apple MOV/MPEG-4 (not produced on Linux) · ProRes 4444 MOV: `prores_ks` profile 4 `yuva444p10le` · MP4 H.264 control: `libx264` `yuv420p` (no alpha) · PNG sequence: `rgba` stills
Browser method	Local HTTP test page (magenta background) + canvas pixel read after drawImage
OBS method	Magenta Color Source + Media Source; screenshot / pixel check
Counts	15 tested · 11 official docs · 24 untested

Caveats (must keep on-page):

Test clips are synthesized with ffmpeg, not exports from the product pipeline.
Linux Chrome / Firefox / Edge / OBS results may not carry over to macOS or Windows (or mobile browsers).
True HEVC-with-alpha could not be produced on Linux (libx265 drops alpha; no VideoToolbox) — all local HEVC cells stay untested.
Official “supports ProRes” ≠ a guarantee that a given UI defaults to Straight vs Premultiplied alpha; editors may still need Interpret Footage.
OBS ran on X11 + software GL; hardware decode paths may differ.

Export transparent WebM or ProRes in the browser

ExportAlpha removes the background and exports:

WebM VP9 with alpha (yuva420p) — for Chrome / Firefox / Edge / OBS (per matrix)
ProRes 4444 MOV (yuva444p10le, profile 4) — editorial / OBS (per matrix)

It does not export HEVC-with-alpha, H.264 MP4 with alpha, or PNG video sequences. Stills export as transparent PNG. Live limits: WebM ≤60s · ProRes ≤8s · upload up to 60s / 1080p / 200MB.

Credits: 1 credit = 1 video second = 1 image. 5 free credits on first sign-in; trial stills capped at 5. Not unlimited free.

Try 5 free credits

Upload a clip and export transparent WebM or ProRes 4444 — formats that match the matrix above.

Try 5 free credits See pricing

Frequently Asked Questions

Which video formats support an alpha channel?

Formats in this matrix that store or keep alpha in at least one documented/tested target: WebM VP9 with alpha, HEVC with alpha (Apple Safari docs), ProRes 4444 MOV, and PNG (stills / sequences — not <video>). Everyday H.264 MP4 does not carry alpha in our control test.

What video format supports transparency?

Pick by destination: WebM VP9 for Chrome / Firefox / Edge / OBS (tested); HEVC-with-alpha for Safari per Apple (docs; untested by us); ProRes 4444 for editors (docs) and OBS (tested). No single row is universal.

Does MP4 support transparency / an alpha channel?

Everyday H.264 MP4: no in our Chrome / Firefox / Edge / OBS tests (plays; transparent area black). Apple HEVC-with-alpha can live in MPEG-4 or QuickTime containers per Apple’s interoperability notes — that is a Safari-oriented exception, not “H.264 MP4 alpha.” Details: MP4 guide.

Do Chrome, Firefox, Edge, and Safari play transparent WebM?

Chrome, Firefox, and Edge: yes, alpha kept (tested). Safari macOS: plays but not transparent (grey background) per WebKit bug #275908 — docs only, not tested by us. Safari iOS WebM alpha: not verified — official sources do not spell out iOS behavior; WebKit bug #275908 is reference only. See WebM × Safari.

What should I use for OBS vs Premiere / Final Cut / DaVinci / After Effects?

OBS: WebM VP9 or ProRes 4444 (both ✓ tested keeps alpha). Premiere / Resolve / After Effects / Final Cut: matrix points to ProRes 4444 via official docs (wording hedged — not lab-tested imports). WebM × those editors: Untested.

Can one transparent file work everywhere?

No row in the matrix is universal. Chrome/Firefox/Edge want WebM alpha; Safari wants HEVC-with-alpha per Apple; editors lean ProRes 4444 per docs; OBS accepted WebM and ProRes in our tests. Export for the destination.