Meshtastic Presets Explained: Long Fast and Beyond

A Meshtastic modem preset is a named bundle of three LoRa radio settings (bandwidth, spreading factor, and coding rate) that trades range against speed. Nodes can only hear each other when they use the same preset, and in most setups the preset also picks which frequency slot the node listens on, so choosing the preset your local mesh uses matters more than picking the “best” one.

All figures below come from the official Radio Settings and LoRa Configuration pages. LoRa Mesh Atlas is independent of the Meshtastic project.

What a preset controls

From the Radio Settings page:

• Spreading factor (SF): “How much we ‘spread’ our data over time.” Each step up doubles airtime and adds about 2.5 dB of link budget.
• Bandwidth: “How big of a slice of the spectrum we use.” Each doubling costs almost 3 dB of link budget.
• Coding rate: “How much redundancy we encode to resist noise.” 4/5 adds 1.25x overhead; 4/8 adds 2x.

Link budget is, roughly, how much signal loss a link can tolerate. More link budget usually means more range, but it comes from slower transmission, which uses more airtime on a frequency the whole mesh shares.

The general-purpose presets

The current (2.8) docs list nine general-purpose presets, ordered from fastest and shortest range to slowest and longest range (Radio Settings). Medium Turbo only works on firmware 2.8, which is still alpha as of October 2026; the current beta (2.7.26) has no working Medium Turbo preset and still lists eight presets.

Preset	Data rate	SF	Coding rate	Bandwidth	Link budget
Short Turbo	21.88 kbps	7	4/5	500 kHz	140 dB
Short Fast	10.94 kbps	7	4/5	250 kHz	143 dB
Short Slow	6.25 kbps	8	4/5	250 kHz	145.5 dB
Medium Turbo	7.03 kbps	9	4/5	500 kHz	145 dB
Medium Fast	3.52 kbps	9	4/5	250 kHz	148 dB
Medium Slow	1.95 kbps	10	4/5	250 kHz	150.5 dB
Long Turbo	1.34 kbps	11	4/8	500 kHz	150 dB
Long Fast	1.07 kbps	11	4/5	250 kHz	153 dB
Long Moderate	0.34 kbps	11	4/8	125 kHz	156 dB

The docs note that these link budgets assume 22 dBm transmit power and a 0 dBi antenna, and that the data rates are theoretical maximums that don’t account for headers, hops, and retransmissions. The calculations are based on Semtech’s LoRa calculator.

The three Turbo presets use 500 kHz bandwidth, which the docs say “is not legal to use in all regions.” They’re unavailable in the European EU_868 region. In the US region they’re available.

Narrowband presets

Firmware 2.8 (alpha as of October 2026) adds Lite, Narrow, and Tiny preset families for specific regions (European SRD bands and amateur radio bands) where wide presets aren’t permitted. They are not usable on the current 2.7 beta. They can’t be selected in the US region, and the Tiny presets require a radio with a precise TCXO, per the LoRa config page. Licensed operators should read is Meshtastic legal in the USA for ham-mode rules.

Long Fast, Long Turbo, and the US default

Long Fast (LONG_FAST) has been the default for years: “a strong mixture of speed and range, for most users,” in the LoRa docs’ words.

Long Turbo in the US. The LoRa docs state that “a US node whose region is first set from its own screen starts on LONG_TURBO instead.” The 2.8 announcement explains why: it says FCC rules for full-power operation at 902–928 MHz (§15.247) set a minimum bandwidth of 500 kHz, and Long Turbo uses 500 kHz while Long Fast uses 250 kHz. That default applies only when the region is set on the device screen for the first time; setting it from an app or CLI leaves the node on Long Fast, and upgrading doesn’t change an existing preset. (2.8.1 was an alpha release as of October 2026.) For what §15.247 actually says, see our legal guide.

The practical consequence: Long Turbo and Long Fast nodes can’t hear each other. If your area runs Long Fast, set your node to Long Fast.

Why every node in a mesh must share a preset

The Joining your local mesh page puts it bluntly: “Two nodes on different presets don’t have a slower link between them, they have no link at all, at any distance.” The LoRa radio can only demodulate a signal whose bandwidth, spreading factor, and frequency match its own.

That’s why communities settle on a single preset together, and why the LoRa docs note that “in order to communicate fully, devices within a mesh must have identical settings for Region and Modem Preset, or identical custom Modem settings.” (The Overview adds that nodes can still receive packets sent with a different coding rate, but presets differ in more than coding rate.)

Frequency slots

How the slot is chosen

The US region spans 902–928 MHz. With Long Fast’s 250 kHz bandwidth, that’s 104 possible frequency slots (Radio Settings). Unless you set a slot explicitly, the firmware picks one by hashing a name:

• If the primary channel’s name is unchanged (blank), the preset name picks the slot.
• If you rename the primary channel, the channel name picks the slot instead (Channel config).

Documented US default slots, from the official docs and blog:

Preset (default primary channel)	Slot	Center frequency
Long Fast	20	906.875 MHz
Long Turbo	14	908.750 MHz
Medium Fast	45	913.125 MHz

Sources: Joining your local mesh and the finding your local mesh blog post.

Don’t rename the primary channel to go private

Because channel 0’s name feeds the slot, renaming it moves your node to a different frequency “and leaves it alone on a mesh of one,” according to the joining guide. To have private conversations while staying on the public mesh, add private groups as secondary channels 1–7. They share the primary channel’s radio settings and slot but use their own keys. Our privacy guide covers channel keys.

Should your mesh move off Long Fast?

The Meshtastic blog post Is LongFast Holding Your Mesh Back? argues that Long Fast’s long airtime causes congestion and collisions as meshes grow. It suggests considering a faster preset if your mesh has:

• more than about 60 nodes, especially close together,
• high message volume from people or automated systems,
• an urban or suburban footprint where throughput matters more than maximum range, or
• noticeable delays or inconsistent delivery.

For dense urban/suburban meshes it suggests Medium Fast or Medium Slow; for extremely dense ones, Short Fast or Short Slow. The post includes accounts from the Bay Area (moved to Medium Slow, 150+ nodes) and Wellington, New Zealand (moved to Short Fast). It also stresses that switching “requires updating all nodes in your mesh,” and describes groups leaving a bot on Long Fast to point stragglers to the new settings.

Firmware also adapts on its own: in meshes over 40 online nodes, it stretches position and telemetry intervals based on spreading factor and bandwidth (Mesh Broadcast Algorithm).

How to find and set your local preset

1. Ask locally. Regional groups publish their settings; see finding Meshtastic nodes near you.
2. Scan. The Android and Apple apps include Local Mesh Discovery, which cycles through presets and ranks them by what it hears. It only sees meshes on the default public channel and default slot (joining guide).
3. Set it. In the apps, go to the LoRa settings and change Modem Preset; with the CLI, meshtastic --set lora.modem_preset MEDIUM_FAST (or another preset). Set your region first.

Choosing a preset also affects range planning; see the range guide and our range tool.

Custom settings

You can turn off “Use Preset” and set bandwidth, spreading factor, and coding rate by hand. The docs list example custom combinations but caution that they “may not have been tested.” Everyone on your mesh would need the same custom values, shared via channel URL or QR code, which carry LoRa settings.