Loom limits uploads to 4 GB or 12 hours, whichever is less. That final clause is the part almost everyone misreads. The two numbers are not a pair you have to breach together, and they are not options you get to pick between — whichever ceiling your file reaches first is the one that refuses the upload.
That distinction matters because the two kinds of rejected files look nothing alike. A short 4K screen capture can be nowhere near 12 hours and still sail past 4 GB. A very long, very low-bitrate recording can sit comfortably under 4 GB and still be over the 12-hour line. Only one of the two has to be true.
The limits, at a glance
Every number below is quoted from Loom's own help pages; the source page is named in the last column.
| What | The limit | Where Loom states it |
|---|---|---|
| Size of one uploaded file | 4 GB | "Upload or import videos" |
| Length of one uploaded file | 12 hours | "Upload or import videos" |
| How the two combine | "whichever is less" | "Upload or import videos" |
| Files uploading simultaneously | "you can upload up to 10 videos at a time" | "Upload or import videos" |
| Total number of uploads | "There is no limit to how many videos you can upload" | "Upload or import videos" |
| Mobile uploads | 4 GB or 12 hours, whichever is less | "Upload or import videos" |
| Accepted containers | "MV, AVI, WEBM, MP4, MOV (Up to 4GB)" | "Loom video encoding settings" |
| Frame rate that triggers a failure | over 60 fps | "Upload or import videos" |
| Resolution that triggers a failure | over 4096 x 2160 | "Upload or import videos" |
| Upload speed Loom asks for | "at least 5 Mbps" | Loom's upload-failure KB article |
| Download cap (a separate number) | 20 GB | "Download your Loom video" |
Two notes on that table. First, MV is how the container list is printed on Loom's own pages — it appears that way in the uploaded-media specification table, so we are quoting it rather than guessing what it was meant to say. Second, the 20 GB figure is a download cap, not an upload allowance. Loom's download page pairs it with its own conversion: "Approx. 3 hours recorded in 4K." Do not use 20 GB as a mental model for what you can push in.
What "whichever is less" actually means in practice
Read the rule as two independent gates with an OR between them: over 4 GB, or over 12 hours, and the upload stops. You never need both conditions.
The practical consequence is that checking one number tells you nothing. People routinely confirm a clip is only 40 minutes long, conclude they are safe, and then watch the upload fail on size. The habit that saves time is to check file size on disk and duration before you start, because either one alone can be the blocker.
Mobile is not a loophole either. Loom states the same ceiling for phones and tablets: mobile uploads are limited to 4 GB or 12 hours, whichever is less.
What Loom does with the file once it is accepted
This is worth knowing because it tells you what format to hand over. Loom's encoding page publishes the specification it applies to uploaded video: container support for MV, AVI, WEBM, MP4 and MOV up to 4 GB, video re-encoded to H.264 at a target of 30 fps with variable bitrate, audio as AAC, 48kHz, 1 Channel (Mono), and resolution "Up to 4K video (360p, 480p, 720p, 1080p, 1440p, 2160p)". Loom then makes the video available "in all resolutions starting with the originally recorded resolution, down to 480p".
So the file is re-encoded regardless. Handing Loom something that is already close to that target is the path of least resistance — which is exactly what Loom itself recommends: "We recommend exporting your video using the media specifications in the above table (H.264/AAC to . MP4 file.)".
When the upload fails anyway
Loom names the three most common causes of a "Failed to process" message directly: the file is over 4 GB, its frames per second are over 60, or its resolution is over 4096 x 2160. Note that Loom's wording is "most often occurs because" — it presents these as the usual suspects, not an exhaustive list.
Two more things from Loom's troubleshooting guidance are worth having in your head:
- Connection. Loom asks for a stable connection with an upload speed of at least 5 Mbps.
- Audio channel count. Loom's upload-failure article names a specific hidden cause: sometimes "an underlying property of your video is not supported (like the number of audio channels is too high)", and it says this can only be fixed by re-encoding the file. A surround-sound track on an otherwise ordinary file is not something the error message will spell out for you.
Loom also describes how uploads behave while they run: your videos keep uploading even if you leave the upload modal, and they only stop if you select cancel. Videos that are large in resolution, size, or duration take longer to process and may sit in a processing state after the upload itself finishes — so a stalled-looking progress bar is not automatically a failure.
Getting a large file under the cap
Loom's own answer is to re-encode: its pages recommend running the file through HandBrake if the format is unsupported or the quality comes out wrong, and exporting H.264/AAC to MP4. That works. It also means installing a desktop application to fix a one-off upload.
If you would rather not, the same job — re-encode to H.264 MP4, drop the file size — can be done in this page:
Try it right here
Runs in your browser. Your file is not uploaded anywhere.
This runs inside your browser tab: the file is read from disk, re-encoded locally, and handed back. Nothing is uploaded to a server, which matters when the video you are trying to move is an internal recording. For longer sources where you want to control resolution and bitrate deliberately rather than accept a preset, use the full video compressor instead.
Two decisions do most of the work when a file is stubbornly large: resolution and bitrate. A 4K capture that will be watched in a player window is carrying pixels nobody sees, and Loom will serve it down to 480p for viewers on poor connections anyway.
Plan and platform gotchas
- Uploading is a paid feature. Loom states that video uploading is available only to users on its Business, Business + AI or Enterprise plans, and that uploads are not available for Business + AI Trials. Loom's Business plan FAQ adds the same restriction for trials: "Please note the Upload feature is temporarily unavailable for Business Trial users." If the upload button is missing, check the plan before you blame the file.
- Starter accounts have a separate wall. Free workspaces are capped at 25 videos in the library — see the Loom 25-video Starter limit for how archived videos count against it.
- Moving videos between accounts uses upload. Loom's documented route for that is to download from one account and upload to the other, and its workspace-transfer page states this requires a paid Loom plan and paid seats on both the source and destination account.
- Ten at a time. There is no limit on how many videos you upload overall, but Loom caps concurrent uploads at 10. Large batches need queueing, not one giant drag-and-drop.
- Downloads come back as MP4. Whatever you upload, Loom states that all videos downloaded from Loom are in MP4 format — useful to know if the upload is step one of a migration.
FAQ
What is Loom's maximum upload file size? 4 GB. Loom's upload page states the rule as "4 GB or 12 hours, whichever is less", so a file under 4 GB can still be rejected for running past 12 hours.
Does Loom allow 12-hour videos? Only if they also come in under 4 GB. The 12-hour figure is the length ceiling, but the size ceiling applies at the same time and the stricter of the two wins.
Is the upload limit smaller on the Loom mobile app? No. Loom documents the same rule for mobile: uploads are limited to 4 GB or 12 hours, whichever is less.
Why does my Loom upload say "Failed to process"?
Loom says this most often happens because the file is over 4 GB, its frame rate is over 60 fps, or its resolution is over 4096 x 2160. A too-high audio channel count is another cause Loom names. Re-encoding to H.264/AAC MP4 addresses all four.
Can I upload to Loom on the free Starter plan? No — Loom limits uploading to Business, Business + AI and Enterprise plans, and excludes Business + AI trials. For anything else about tier ceilings, browse the limits explainers.
How many videos can I upload at once? Up to 10 at a time, with no stated limit on the total number of uploads.
Figures cited from Loom's help pages for uploading, encoding settings and downloading, checked 16 September 2026. Loom's documentation changes — verify the current numbers in the official documentation before planning a large migration. For browser-based conversion and compression, see all Clapr tools.
