Answer
Your client's video keeps buffering on slow internet.
Here is why, and three honest fixes.
On uncompressed.io every film plays from one file, the one you uploaded, in a plain video player. There is no lower-quality copy to fall back to, so when the client's connection is slower than your file's bitrate, the film stops to load instead of dropping to 480p. You can let it load first, give the client a lighter export, or let them download the file. If most of your viewers are on slow connections and picture fidelity matters less than smooth playback, an adaptive host such as Vimeo or YouTube is the better choice.
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By uncompressed.io · Updated September 2026
Why it buffers
One file, one bitrate,
and nothing smaller to switch to.
A film plays smoothly only while the connection delivers data at least as fast as the film uses it. Your export has a bitrate. If the client’s connection is slower than that bitrate, the player runs out of data and stops to wait.
Most large platforms hide this with adaptive streaming. MDN describes the method: the host provides several different quality files, split into chunks over time, and the player picks between them as it goes. YouTube’s help page lists the speed of the viewer’s internet connection as one of the factors that decide the quality they see, with an Auto setting that changes quality for the viewer’s conditions. Vimeo publishes a ladder of renditions with maximum bitrates from 0.3 Mbps at 240p to 2.5 Mbps at 720p and 22 Mbps at 4K. On a slow link, those players drop to a lower rung and keep playing.
uncompressed.io does not do this, on purpose. Every watch page and embed hands the player a single file, the export you uploaded, with no re-encode and no lower rungs. The upside is that the client sees your actual export whenever the connection keeps up. The downside is the one your client just hit: when it does not keep up, the film pauses to load. It never quietly becomes 480p, and it also never quietly saves the viewing.
The arithmetic
Check the numbers
before you send the link.
Compare your file’s bitrate with the client’s connection. The table works through a 10-minute film at four bitrates, on a steady 10 Mbps and a steady 25 Mbps connection.
Idealized arithmetic, our own: pause time = length x (file bitrate / connection speed - 1); whole file = length x file bitrate / connection speed. Real connections fluctuate and a variable-bitrate export runs above its average in busy shots, so real waits are longer. 16, 32 and 80 Mbps sit inside our recommended review ranges; the 6 Mbps cut is an example below them.
Two things follow. First, a file below the connection speed has room to play, and a file above it does not, however long the client is patient in the moment. Second, the gap grows fast: an 80 Mbps 4K master on a 10 Mbps connection needs more than an hour of loading before a 10-minute film can play through. Ask the client to run a speed test and tell you the download figure. It takes a minute and tells you which fix to use.
Three honest fixes
Each one has a cost,
pick the one that fits the client.
Let it load first
Ask the client to press play, pause at once, and come back later. How much a browser loads while paused is its own choice, so this works best when the file is only a little above their connection speed.
Send a lighter export
Export a smaller review copy that sits under their connection with room to spare, and share that. It looks softer than the master; that is the trade. Our recommended review ranges are 16 to 32 Mbps for 1080p HEVC and 40 to 80 Mbps for 4K HEVC at 24 or 30 fps, and a client on a slow link may need less.
Turn on the download
Switch on the original-file download for that film. The client pulls the whole file once, at whatever speed they have, then plays it from their own disk with no stalls from the connection. The download takes about as long as the table's whole-file figures say.
Where the lighter copy lives
On a paid plan, upload it as its own film, or add it as another version of the film in the review room. On the free Starter plan, which holds one film at a time, it has to replace the master behind the same link instead of sitting beside it.
What the lighter copy costs
Storage. Each copy you keep counts against your plan's space, so a master plus a review cut uses both files' sizes. Delete the review cut once the client has signed off.
What the download costs
Control. Once the file is on the client's disk, it is theirs to keep. For a cut you have not been paid for, keep the download off and use a lighter, marked export instead.
What never changes
The link. Replacing a film's file keeps its address, so you can swap a lighter review cut for the master later, or the other way round, without sending a new link.
When to use another host
If smooth matters more than exact,
use an adaptive player.
We would rather lose the viewing than pretend. If your audience is mostly on slow or mobile connections and they need to watch through without stopping, Vimeo or YouTube will serve them better, because their players drop quality to keep going.
That is the right call for a public launch, a social cut or a client watching on a phone in a car park. It is the wrong call when the point of the link is to judge the picture: a grade, fine grain, shadow detail or a 4K finish. A 720p rung capped at 2.5 Mbps, per Vimeo’s own table, cannot show a client what your master looks like. For that job, a short wait or a download beats a smooth picture that is not your film. If the client already saw a soft image rather than a pause, the 480p diagnosis guide explains which side dropped the quality.
What we do not promise
Questions
Frequently asked
Can uncompressed.io lower the quality automatically when the connection is slow?
No. The player receives one file, the one you uploaded, and there is no set of lower-bitrate versions for it to switch to. A slow connection makes the film pause to load. It never falls back to a smaller picture on its own.
Will pausing the video let the whole film load?
Often, but not with any guarantee. Our player sets no preload hint, so each browser applies its own default, and MDN notes that the default differs between browsers and that preload is only a hint. If a pause does not build enough of a lead, the download switch is the reliable route.
Does exporting in HEVC instead of H.264 help?
It can. Our recommended 1080p review range at 24 or 30 fps is 16 to 32 Mbps in HEVC against 24 to 48 Mbps in H.264, and MDN says HEVC can theoretically reach half the file size of AVC at comparable quality. The catch is decoding: the client's device must play HEVC, which is why the guide on unplayable 4K files is worth a look before you switch.
Should I just use Vimeo or YouTube for this client?
If the client is on a slow or unreliable connection and the goal is simply for them to watch the film through without stopping, yes. Those players switch between versions of different quality to keep playing. If the goal is for the client to judge the actual grade and detail of your export, a lower rendition defeats the purpose, and a download or a pause to load is the better trade.
Pick the plan for the files you keep
Every plan streams the file you uploaded, the free Starter plan included (5 GB, one film at a time). A lighter review copy next to the master takes its own space, so size the plan for both.
Sources
- 1.MDN Web Docs, Setting up adaptive streaming media sources: several quality files split over time points; DASH and HLS (fetched 18 September 2026)
- 2.MDN Web Docs, the video element: the preload attribute is a hint and its default differs by browser (fetched 18 September 2026)
- 3.YouTube Help, Change video quality: Auto, and internet connection speed as a factor (fetched 18 September 2026)
- 4.Vimeo Help, Guidelines for determining playback resolution: maximum bitrate per rendition (fetched 18 September 2026)
- 5.MDN Web Docs, Web video codec guide: HEVC compared with AVC (fetched 18 September 2026)