TL;DR: A Runway export is a standard ISO Base Media container — MP4 (H.264) on Basic and Standard plans, with ProRes 4444 added on Pro and Unlimited per Runway's export docs. The identifying data sits in three places: the mvhd movie header (creation and modification timestamps as seconds since 1 January 1904 UTC), the udta and meta sub-atoms of moov (encoder string in ©too, software tags, Apple QuickTime keys), and an optional XMP packet from any editor it passed through. Opening the file in Metadata Cleaner and clicking Clean rewrites all three without touching a frame. Verify with exiftool -G1 -a clean.mp4. The strip cannot reach the free-plan visible watermark, server-side records Runway keeps, or a pixel-domain AI watermark a future release might add.
This is the step-by-step companion to our earlier piece on what's actually in a Runway export. That post explained the structure; this one walks the strip itself, one click at a time, with verification commands you can run after.
What You Need Before You Start
Three things. First, the file you actually exported from Runway — not a screen recording or somebody else's re-encode. The download button on the project page hands you that file directly; that is what carries the moov metadata we are clearing. A second-hand copy will have other editors' tags layered on top, and the strip clears them the same — but you should know what you are looking at.
Second, a modern browser: Chrome, Safari, Firefox, or Edge, desktop or mobile. No extension, no account, no CLI. The tool runs as a WebAssembly worker in the page.
Third, optional but recommended: ExifTool for verification — Phil Harvey's open-source utility, at exiftool.org, which reads QuickTime and MP4 atoms with more depth than any GUI inspector. macOS: brew install exiftool. Linux: your package manager. Windows: the standalone executable. For a GUI, the free MediaInfo app reads the same fields.
Photo by Nemuel Sereti on Pexels.
The 30-Second Browser Strip
This is the path we recommend for almost everyone. No install, no CLI, same on a phone or a laptop.
- Open Metadata Cleaner in a fresh tab. The page loads its WebAssembly bundle. You can confirm nothing is uploading by opening the browser's network tab — once cached, the file you drop in produces zero outgoing requests.
- Drag the Runway export onto the drop zone, or click to pick. On a phone, tap and choose Files or Photos. The browser reads the file into the tab's memory.
- Click Clean. The worker parses the ISO Base Media container, finds the
moovatom, drops theudtaandmetasub-atoms, zeroes the timestamps inmvhd, and removes any XMP packet. It writes a new container with the originalmdatsample data copied through. No re-encode, no quality change, no frame altered. - Click Download. By default the tool writes a new filename so you can keep both side by side until you confirm the strip worked.
A ten-second 1080p clip cleans in well under a second on a modern laptop. A two-minute ProRes 4444 file takes a few seconds because the container is much larger, but time scales with file size, not video length. The picture stays byte-identical at the mdat level — what changes is the boxes around it.
How to Verify the Strip Worked
Three checks, in rising order of thoroughness.
Shallow — OS file inspector. Right-click the cleaned file and pick Properties (Windows) or Get Info (macOS). The OS shows a filesystem creation date — when your machine wrote the file to disk, not what is inside it — and sometimes the encoder string. A useful sanity pass before upload. Not authoritative.
Standard — ExifTool. From a terminal in the same folder, run exiftool -G1 -a -u clean.mp4. The flags matter: -G1 shows each tag's group ([QuickTime], [ItemList], [XMP], [Track1]), -a prints duplicates instead of collapsing them, and -u forces unknown tags to print so nothing hides. After a clean you should see no [QuickTime] Encoder, no [QuickTime] Software, no [QuickTime] CreateDate, and no [XMP] group at all. What remains — MajorBrand, CompatibleBrands, Duration, image dimensions — is structural, not identifying.
Detailed — MediaInfo. Run mediainfo clean.mp4 or open the file in the GUI. The General section normally lists Encoded date, Tagged date, Writing application, and Writing library. On a cleaned file all four are absent. Video and audio sections — bitrate, frame rate, codec, sample rate — stay the same.
If a field you expected to disappear is still there, the most likely cause is that you ran the verifier against the original file rather than the cleaned one. Re-check the path.
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The CLI Alternatives, and When to Reach For Them
Two command-line tools do the same job. We list them because batch jobs and pipelines sometimes need them — not because they replace Metadata Cleaner for everyday use.
ffmpeg -i input.mp4 -map_metadata -1 -c copy output.mp4 is the workhorse. The -map_metadata -1 flag tells FFmpeg to drop all global and stream-level metadata; -c copy skips re-encoding so streams pass through byte-for-byte. The right call for a folder of fifty Runway exports cleaned in a shell loop.
exiftool -all= -overwrite_original clean.mp4 uses ExifTool's writer to strip every tag it knows how to write. The -overwrite_original flag suppresses the .original backup. ExifTool is excellent at QuickTime atoms and XMP, though it can leave a few structural entries that FFmpeg and Metadata Cleaner clear more aggressively.
When does the CLI beat the browser tool? Batch jobs, server-side automation (a render farm that wants a clean step before upload), and pre-commit hooks in repos that version video assets. For a one-off clip you are about to post, the browser tool is faster and harder to misuse.
The Mobile Path
Most questions about cleaning a Runway file come from phones, because Runway has a mobile app and the export-then-upload loop happens on the same device. The procedure is the same; only the gestures change.
On iOS, the export usually lands in Files under a "Runway" or "Downloads" folder. Open Safari, go to metadatacleaner.app, tap the drop zone, pick the file. After cleaning, tap Download — iOS saves the result back to Files or shares it to another app. Going straight from Metadata Cleaner to the TikTok or Instagram upload sheet via the iOS share sheet is the cleanest phone-only workflow.
On Android the path is nearly identical. Chrome or Firefox both work; the file is usually in Downloads/ or a tool-specific folder. The drop zone accepts files from the system picker, and the cleaned result lands back in Downloads/.
One quirk: some phone photo apps stamp their own metadata onto a video the moment you save it to the camera roll. Keep the Runway file in Files (iOS) or Downloads (Android), feed it directly to Metadata Cleaner, and upload from there.
Photo by Mikhail Nilov on Pexels.
Edge Cases: ProRes 4444, MOV Containers, and the Free-Plan Watermark
A few situations come up often enough to address directly.
ProRes 4444 from Pro and Unlimited plans. Runway exports ProRes in a MOV container — QuickTime's native wrapper. MOV and MP4 share the ISO Base Media File Format heritage, so the moov, mvhd, udta, and meta boxes live in the same places. The strip works the same way. The clean takes a few seconds rather than a fraction of a second only because the file is larger.
MOV-specific tags. A MOV file can carry Apple-specific QuickTime keys like com.apple.quicktime.creationdate and com.apple.quicktime.software, stored in a keys/ilst structure that Metadata Cleaner clears as part of the moov rewrite. To see them by name in a verification dump, ExifTool's -keys group lists them.
The free-plan visible watermark. Runway burns a visible watermark into the exported frames on the free tier. That mark lives in the encoded pixel values inside mdat, not in any metadata atom — so no metadata strip can touch it. The only ways to get a clean frame are a paid plan or destructive cropping. Cleaning metadata is not the same as removing a watermark.
Round-tripped clips. A clip that went through Premiere, DaVinci Resolve, or Final Cut before export will carry additional XMP packets and editor-specific tags. Metadata Cleaner removes the XMP block entirely and any editor tags inside udta go with it. After the strip, ExifTool's -XMP:all group is empty.
What Stripping Doesn't Reach (Honest Limits)
The boundary matters more than the procedure. Four things a metadata strip does not do.
No pixel-domain watermark removal. Google's SynthID, which marks Veo output, encodes signal into the sample values themselves and is designed to survive compression, cropping, and re-encoding. Runway is not currently known to embed a pixel-domain watermark, but the rule holds for the category: a signal in the samples is not in the header, and a container clean cannot reach it. Same header-versus-signal split we covered for audio in metadata versus watermarks.
No server-side erasure. Whatever Runway logs about the generation — prompt, account, model version, timestamp — lives on their infrastructure independent of the file you downloaded. Cleaning what you hold does nothing to records you do not.
No guaranteed platform classification. TikTok, Instagram, and YouTube run their own pipeline at upload, reading provenance signals where they exist and falling back to content-based classifiers where they do not. A clean container removes one input to that process. It is not a guarantee. We covered the platform side in how platforms read AI metadata at upload.
No new signing. Some workflows want to add a C2PA Content Credential to a clean file. Metadata Cleaner strips; it does not sign. For signed provenance the C2PA specification and the Content Authenticity Initiative point at the tools that do.
Cleaning a Runway export reliably clears the timestamps and tool strings that ride along inside the container — the part most people are trying to keep off their uploads. One clean layer, not the whole stack.
FAQ
Does stripping change the video quality?
No. The clean rewrites only the container boxes around the sample data. Encoded video and audio streams are copied through unchanged — same resolution, bitrate, frame rate, color. Run ffprobe before and after and the stream-level numbers match.
Will the cleaned file still upload to TikTok, Instagram, and YouTube?
Yes. MP4 (H.264) and MOV are universally accepted, and platforms do not require metadata. The cleaned file is typically a few kilobytes smaller than the original.
Does this handle Runway's ProRes 4444 exports?
Yes. ProRes inside a MOV container uses the same ISO Base Media File Format boxes as H.264 inside MP4, so the strip path is identical. The clean takes longer only because the file is larger.
Can I do this entirely on my phone?
Yes. Metadata Cleaner is browser-only, so any modern mobile browser works. The drop zone becomes tap-to-pick on iOS and Android. The cleaned file goes back to Files or Downloads for re-upload.
Will a clean remove Runway's visible free-plan watermark?
No. That watermark is rendered into the picture itself, not stored in metadata. Removing it requires a paid plan or a destructive crop.
Is removing video metadata legal?
Yes, for files you own. No jurisdiction we know of requires civilians to preserve creation timestamps or encoder tags on personal files. Narrow professional contexts — broadcast chain-of-custody, evidentiary submissions — have their own rules; outside those, stripping is your call. The EFF's privacy issues page is a good general read on why most creators clear metadata before posting.
Cleaned your Runway clip yet? If not, this is the part of the post where it costs you about a minute. Try Metadata Cleaner free — drop the file, click Clean, download. The frames are yours; the boxes around them do not have to come along.