2026-09-26

Microsoft Teams caps a video attached directly in chat at 100MB — its own docs put file uploads at 250GB just one tab over

The video that won't attach in a Microsoft Teams chat is rarely a large one by video standards — it's often a 90-second phone clip or a short screen recording, the kind of file that moves without a second thought in an email or a text. Teams bounces it with a size error while, elsewhere online, people describe Teams as a place that comfortably holds files in the hundreds of gigabytes. Both things are true. Microsoft's own limits page just never puts them in the same sentence.

One page, two numbers, and a very different unit

Microsoft's own "Limits and specifications for Microsoft Teams" page states the chat number plainly, in the Messaging > Chat table: "File size limitation — 100 MB," alongside "Number of file attachments — 10," with a footnote warning that "if the number of attachments exceeds this limit, you see an error message." That's the number a file hits the instant it's dropped straight into the message box of a 1:1 chat, a group chat, or a channel conversation. Scroll further down the same document to its Storage section — covering the SharePoint backend behind the Files tab and OneDrive-shared links — and the per-file ceiling listed there is 250 GB, repeated identically across every Microsoft 365 and Office 365 plan in the table, from Business Basic up to Enterprise E5. Twenty-five hundred times larger, on the same page, for the same product.

Why the small number is the one people actually hit

The gap isn't a typo — it's two different delivery pipes. A file attached directly to a chat message travels as a lightweight inline attachment; a file placed in a channel's Files tab, or shared as a link, goes through SharePoint's document library and OneDrive for Business, the same backend Teams' 250GB figure describes. Most people never choose between the two on purpose — dragging a clip into the box you're already typing in is the obvious move, and it's exactly the path capped at 100MB. The same Microsoft page adds a detail that matters for anyone on the receiving end of an outside conversation: "Users in private chat also can't share files because OneDrive for Business (which is tied to the SharePoint license) is required for that functionality." For a guest or an external contact whose organization doesn't provide that license, the Files-tab workaround isn't a click away — the 100MB chat cap is the only door available, full stop.

How fast an untouched phone clip finds that 100MB wall

The 100MB chat cap sounds generous until the file involved is a phone recording nobody has re-encoded. Apple's own support page on compressing a video on iPhone puts a default iPhone Camera recording at 1080p — the default iPhone camera and iMovie export settings — at 70-105MB per minute. Run the 100MB chat ceiling against that range and a completely ordinary, untouched clip clears it in well under two minutes: as little as 57 seconds at the high end of Apple's own figure, under a minute and a half even at the gentler end. Forward that clip straight from a camera roll into a Teams chat message and the "file too large" error isn't really about the video being unusually big — it's the default output of a phone camera meeting a cap sized for something smaller.

What actually fits in 100MB, once it's re-encoded

NearVid's WebM export uses three fixed bitrate presets — 2Mbps video for High, 1Mbps for Medium, 500kbps for Low, plus roughly 128kbps of audio — the same numbers behind the "≈" size estimate the export screen shows before anything encodes. Run a 100MB budget against those and the picture looks very different from a raw phone clip: roughly 6 minutes 16 seconds at High, roughly 11 minutes 49 seconds at Medium, and roughly 21 minutes 14 seconds at Low. The browser-native MP4 path uses its own presets (4Mbps/2Mbps/800kbps), fitting roughly 3 minutes 14 seconds at High, 6 minutes 16 seconds at Medium, and 14 minutes 22 seconds at Low over the same 100MB. Treat every figure as a labeled estimate, not a promise — the encoder spends bits on whatever is actually in the frame, so a mostly-static screen recording tends to land under these numbers and a busy, high-motion clip can land over.

The workflow: trim to the moment, then convert if you're still over

If you have access to a channel's Files tab or a working OneDrive-for-Business link, that's the simplest path for anything genuinely large — no re-encoding needed, up to 250GB. But for a quick attachment dropped straight into a chat, or for a guest contact without a OneDrive-for-Business license where the chat box really is the only door, the lever that matters most is duration. NearVid's Trim performs a lossless stream copy — no re-encoding, no quality loss, done in well under a second for most files — so cutting a five-minute screen recording down to the twenty seconds where the actual bug or the actual moment happens usually clears 100MB on its own, at full original quality. If the trimmed result is still too big, Convert to WebM or (where the browser supports it) Convert to MP4 offers the High/Medium/Low presets above with an estimated output size shown before you commit — pick whichever one clears 100MB before spending the time to encode. Every step runs in the browser tab, on-device; nothing uploads anywhere until the finished file is dropped into Teams.

What this doesn't do

NearVid doesn't know Teams' cap directly and has no "target exactly 100MB" button — the "≈" figure is an estimate you check against, not a guarantee, so it's worth glancing at the finished file's actual size before sending. It also can't create a Files-tab upload, fix a missing OneDrive-for-Business license, or change anything about SharePoint permissions — those live entirely on Microsoft's side. And if what needs sharing genuinely is a long, full-quality recording rather than a short clip, no preset here beats simply using the Files tab or a shared link when that option is actually available.

The honest summary

Per Microsoft's own limits page, a video attached directly to a Teams chat message is capped at 100MB, while the same product's Files tab and OneDrive-shared links, backed by SharePoint, allow up to 250GB per file — and guests without a OneDrive-for-Business license only ever see the smaller number. Apple's own figures show why that 100MB cap gets hit so often: an untouched default-quality iPhone recording clears it in under two minutes. A lossless trim down to the actual moment, followed by a convert with a size estimate checked before encoding, gets a clip under that ceiling entirely on-device — without needing the Files-tab workaround at all.