LINE Calls Cutting Out, Delayed or Silent? Fix Audio and Network Problems
LINE calls use modest bandwidth but require steady two-way delivery. A fast download result cannot rule out a saturated upload, jitter, packet loss, the wrong audio device or an app permission problem.
Separate an audio-device problem from a network problem
Use the phone's recorder to capture your voice and play a local video through the speaker. If recording or playback fails outside LINE, fix the operating-system permission, selected audio output or hardware before changing the router.
During a LINE call, confirm audio is not routed to earbuds, a car system or another Bluetooth device. Disconnect Bluetooth for one controlled call. If only the other person cannot hear you, focus on microphone input and upload; if neither side is stable, test the connection.
Measure the indicators that calls actually need
Voice packets are small, but late or missing packets cannot be hidden by high peak Mbps. Test upload speed, idle latency, loaded latency and jitter. Where possible, observe packet loss for several minutes at the place where calls fail.
Photo backup, security cameras, live streaming and file sync can fill upload capacity and make calls break up. Pause them one at a time or inspect router traffic. If loaded latency improves, configure supported SQM or QoS using a value slightly below stable measured capacity.
Compare Wi-Fi and cellular without changing everything
Make a short test call on home Wi-Fi and another on cellular where coverage is safe and data charges are understood. Only home Wi-Fi failing points toward interference, signal, the router or ISP; both failing points toward LINE, the phone, permissions or the remote participant.
On Wi-Fi, test near the primary router and then on Ethernet through a computer version if available. Avoid walking between mesh nodes during the comparison. On cellular, weak indoor coverage and tower congestion can also create jitter even when signal bars look adequate.
Check LINE, permissions, battery rules and routing
Update LINE from the official app store and update the operating system. Confirm microphone, camera and local-network permissions as applicable. Allow required background activity during calls and temporarily disable aggressive battery or data-saving rules.
Pause VPN, proxy, private DNS or security filtering only when policy permits, then repeat the call. If a closer VPN endpoint helps but direct routing fails, save timestamps and network details; do not keep random VPN settings without measuring privacy, cost and performance effects.
Isolate the participant, group size and region
Test with a second contact. If failure happens only with one person, that person's device or network may be responsible. In a group call, note whether quality drops when a particular participant joins or when cameras are enabled.
Cross-border calls travel farther and may cross congested interconnections. Compare voice-only and video, another time of day and a second network. A DNS change rarely repairs an established real-time route; evidence is more useful when reporting persistent regional problems.
Collect evidence before reinstalling or reporting
Record time, connection type, phone model, OS and LINE versions, which side lost audio, and upload/latency results. Check LINE's official incident information before reinstalling.
Reinstall only after confirming chats and account access are safely backed up according to LINE's current instructions. Do not erase the phone or disable router security for a calling problem. Share non-sensitive diagnostics with LINE, the ISP or workplace IT as appropriate.
Frequently asked questions
Why does LINE lag when my speed test is fast?
Calls depend on stable upload, low jitter and low packet loss. A high download peak can coexist with upload saturation or brief Wi-Fi drops.
Why can the other person not hear me?
Check microphone permission, selected Bluetooth input and a local recording first, then test upload stability. This distinguishes audio capture from the network.
Will changing DNS reduce LINE call delay?
Usually not after the call is connected. Real-time quality mainly depends on routing, distance, jitter and packet loss.
Should I reinstall LINE immediately?
No. First test permissions, audio devices, another network and service status. Confirm chat backup and account recovery before any reinstall.
Measure upload and latency on the connection where LINE calls break up.
Test call connection