Which client do I use after converting VLESS to sing-box?

Use an official sing-box 1.11+ client (SFI, SFA and SFM included). Versions below 1.11 reject the route rule actions this config uses and fail to load.

Is this VLESS converter free, and does it upload my node links?

It is free and needs no account. The conversion is done by JavaScript inside this page, on your own machine: links are never uploaded, never written into the page URL, and never stored. Closing the tab is all the cleanup there is.

Can I convert a subscription link straight to sing-box?

Yes, but paste the body the subscription URL returns — usually one long base64 string — rather than the URL itself, which the browser cannot fetch across origins. Mixed protocols in one subscription are fine.

The sing-box config converted fine but will not connect — what now?

This page only translates links into a config: it checks the structure, never whether the server is reachable. Confirm the same link works in the client you copied it from, then check the client version — server_ports and route rule actions need sing-box 1.11 or newer.

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Local configuration tool

VLESS to sing-box JSON

Emits uTLS and REALITY blocks in sing-box's nested shape, with a selector outbound ready to use.

Your links stay on this device

Conversion happens entirely in your browser. Links are not uploaded, saved, or placed in the page URL.

Conversion result

Generated sing-box JSON

Why some links are rejected

A parameter that cannot be mapped without changing how the connection behaves is reported rather than dropped. For sing-box that mostly means XHTTP, a transport it does not have at all, plus certificate pinning and TUIC v4 tokens. Renames that sing-box does read — reduce_rtt becoming zero_rtt_handshake — happen here instead of failing quietly on your device.

How to import into sing-box

Save the JSON as your config file, or import it as a local profile in SFI, SFA or SFM. The Proxy selector outbound is already wired up, so switching nodes does not mean editing the file.

How VLESS fields map to sing-box

What this converter actually does, line by line. On the left is how it is written in a VLESS link; on the right is the field it becomes in the sing-box config.

In the link	In the sing-box config	Notes
`uuid@host:port`	`uuid / server / server_port`	The part before @ is the UUID; anything that is not a valid UUID is rejected.
`security=tls`	`tls.enabled: true`	Without security=tls the link is treated as plaintext and the TLS-only parameters below are rejected.
`security=reality + pbk / sid`	`tls.reality.public_key / short_id`	sid must be hex of even length, 16 characters at most.
`sni`	`tls.server_name`	Falls back to the server address when absent. Each client spells it differently: servername in Mihomo, server_name in sing-box, serverName in Xray.
`fp`	`tls.utls.fingerprint`	Defaults to chrome. An unrecognised fingerprint is an error, not a silent fallback.
`alpn`	`tls.alpn`	Comma-separated in the link, an array in every target format.
`flow=xtls-rprx-vision`	`flow`	Passed through as-is. It only means anything over TCP with TLS or REALITY.
`type=ws + path / host`	`transport.type: "ws"`	host becomes the Host header. ed and eh become max-early-data and early-data-header-name.
`type=grpc + serviceName`	`transport.service_name`	gun mode only; mode=multi is rejected.
`type=h2 / type=http`	`transport.type: "http"`	Xray has removed the HTTP/2 transport, so that target refuses the line instead of rewriting it as XHTTP — a different protocol on the wire.
`type=xhttp`	Rejected with an error	Mihomo needs 1.19 or newer and Xray needs 24.11 or newer; sing-box has no XHTTP transport at all, so that target rejects the line.
`type=httpupgrade`	`transport.type: "httpupgrade"`	Mihomo models HTTPUpgrade as a flag on WebSocket; the other two make it its own transport type.
`allowInsecure=1`	`tls.insecure: true`	Converted with a warning — turning certificate checks off gives up protection against interception. Xray removed the option in favour of certificate pinning, so that target refuses the link.
`packetEncoding`	`packet_encoding`	packet-encoding and packetEncoding are accepted as the same parameter.
`pqv / spx / pcs / vcn / ech`	Rejected with an error	REALITY fields added after 2024 that have no faithful equivalent yet — reported rather than dropped.

FAQ

Which client do I use after converting VLESS to sing-box?: Use an official sing-box 1.11+ client (SFI, SFA and SFM included). Versions below 1.11 reject the route rule actions this config uses and fail to load.
Is this VLESS converter free, and does it upload my node links?: It is free and needs no account. The conversion is done by JavaScript inside this page, on your own machine: links are never uploaded, never written into the page URL, and never stored. Closing the tab is all the cleanup there is.
Can I convert a subscription link straight to sing-box?: Yes, but paste the body the subscription URL returns — usually one long base64 string — rather than the URL itself, which the browser cannot fetch across origins. Mixed protocols in one subscription are fine. Subscription to sing-box converter
The sing-box config converted fine but will not connect — what now?: This page only translates links into a config: it checks the structure, never whether the server is reachable. Confirm the same link works in the client you copied it from, then check the client version — server_ports and route rule actions need sing-box 1.11 or newer.

Other converters

All formats in one page VLESS to Clash / Mihomo YAML Convert VLESS to Xray VMess to sing-box converter Trojan to sing-box JSON Convert Hysteria2 to sing-box TUIC to sing-box converter Subscription to sing-box JSON Convert VMess to Clash

This creates a one-time local configuration, not an auto-updating subscription. It checks configuration structure, not whether a server is reachable.