Transparency

What KepFai can archive — and what it can't

LINE places per-file caps on what its Messaging API delivers to bots. KepFai archives every file the API delivers, the moment it arrives. This page tells you exactly where the reliable line sits, why, and what to do for files above it.

See KepFai plans Compare with LINE Premium

At a glance

Per-file caps across each surface

LINE's limits depend on which surface a file moves through. The table below shows the cap that applies in each lane, so you can see at a glance where KepFai sits in the picture.

Surface	Per-file cap
Personal LINE (free or Premium) — posting in a chat	1 GB
LINE Premium (Thailand) — per-file send cap	Same 1 GB — Premium does not raise the per-file limit
LINE Premium — cloud storage for your own backup	100 GB (this is a different thing — personal backup, not send cap)
LINE Messaging API — bot SENDS a file to a user	Image 10 MB · Video 200 MB · Audio 200 MB
LINE Messaging API — bot DOWNLOADS a posted file	Not publicly documented; community evidence points to platform caps similar to the send limits
KepFai — single-file download	Bounded only by R2 + your plan storage
KepFai — "Download all" zip	Up to 500 files per zip · No total-byte cap (ZIP64 streaming)

The honest summary: a member can post a 1 GB file in your group, but whether the LINE Messaging API will deliver that file to a bot like KepFai is not guaranteed by LINE's documentation. KepFai is best-effort — we archive every file the API delivers, and we cannot archive a file the API declines.

Side by side

What each option does for your group

Personal LINE (free)

Members can send files up to 1 GB in chat

LINE keeps the file's download link available for about 7 days; after that the link expires
No long-term group archive — files vanish from LINE after 7 days

KepFai captures each file the moment it's posted, so we beat the 7-day expiry

LINE Premium (Thailand)

Same 1 GB per-file send cap as free LINE
Adds 100 GB of LINE-cloud storage for the user's own backup
Premium Backup extends the user's own chat-history retention

Does not raise the per-file send cap
Does not extend the file-content URL that the Messaging API uses
Does not change what the Messaging API delivers to a bot like KepFai

Bottom line: great for personal backups; does not improve KepFai's archival reach. Don't subscribe to LINE Premium expecting KepFai to capture larger files — that's not how the integration works.

KepFai (any plan)

Archives every file the LINE Messaging API delivers, the moment we receive it
Per-plan retention from 12 months on Starter to indefinite on Lifetime
Single-file retrieval works for any archived file regardless of size
"Download all" uses ZIP64 streaming — no total-byte cap; the bound is 500 files per zip

Cannot archive files the LINE Messaging API declines to deliver (very large files may hit an undocumented platform cap)
Cannot archive files that expired before our capture ran (rare — would require a webhook outage longer than 7 days)

Other places your group may also want to use

LINE's own chat-history backup (Personal / Premium) — for each member's own device. Not group-accessible.
Google Drive / Dropbox / iDrive — members upload very large files there and post the link in the group. KepFai captures the link as text (when text recording is on for the chat).
A managed file-share service — for groups that routinely exchange 500 MB+ files, a dedicated managed share is a better fit than chat archival.

Our promises

What KepFai commits to — and won't pretend

Best-effort capture

We attempt to download every file event the LINE webhook delivers and archive everything LINE returns.

No size guarantee

Files above what the LINE Messaging API returns to bots will not be archived. KepFai cannot work around LINE's platform caps.

Transparency on failure

Capture failures (download error, oversize) are recorded in our audit log with the file's message ID so the operator can investigate. We don't burn push quota notifying members per failure; the group-member consent notice discloses the risk up front.

Reliable bands

Files within the documented Messaging API limits — image 10 MB, video and audio 200 MB, file 200 MB — are the reliable band. Above that, archival is best-effort.

Practical guidance

If your group routinely shares files larger than ~100 MB

Ask members to:

For images: keep the originals (don't compress in LINE). They stay well under the reliable band.
For video and audio: 200 MB is the safe upper bound.
For very large documents (more than 200 MB): upload to Google Drive, Dropbox, or OneDrive and post the link in the chat instead of the file itself. KepFai will archive the text message containing the link (when text recording is on for the chat — see "Record text messages" on your account page).

When LINE changes its limits

We rerun the research pass and update this page

When LINE publishes a Messaging API update — or the developer community reports new behaviour — we rerun the documentation-first research pass and update both this page and the bot's consent notice. Counsel re-reviews any binding language before the change takes effect.

Last reviewed: 23 May 2026

Ready to add KepFai to your groups?

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