
Free
About
Heard a signal you can't identify? Bandline narrows 520 known
signals down to a handful — from what you can actually measure.
Enter a frequency, hold your phone to the receiver, or match a
waterfall shape by eye. Everything works offline, in the field,
with no account and no connection.
— THREE WAYS IN —
BY FREQUENCY
Type any frequency and see the full allocation stack: primary and
secondary service, national applications, footnotes, licence class
and power limits. Then see which known signals actually live in
that band, ranked by how commonly they're heard.
BY EAR (the interesting one)
Hold your phone near the receiver's speaker, or plug in a line-in
cable. Bandline records a short sample and measures:
- occupied bandwidth (−26 dB)
- autocorrelation peaks (ACF, in milliseconds)
- tone count and tone spacing for MFSK
- estimated symbol rate
- burst length, duty cycle, on/off periodicity
- modulation class (AM, FM, SSB, PSK, FSK, OFDM-like)
Each measurement becomes a filter. The candidate list narrows as
you go — 520, then 12, then 3. Drop a chip if a reading looks off.
Every measurement shows a confidence indicator, because measuring
through a phone mic is honest work but not laboratory work.
BY SHAPE
Browse a visual grid of reference waterfalls, filtered by band and
category. You already know what CODAR and STANAG look like — this
is faster than reading a list.
— SIGNAL CARDS —
Name and aliases, category, active status, frequency ranges,
modulation, bandwidth, ACF, symbol rate and mode. A reference
waterfall you can pinch-zoom and compare side by side with your own
capture on a matched frequency axis. A playable audio sample with a
live spectrogram. Protocol notes and links to specifications and
decoder software.
— ALLOCATIONS —
Switzerland, Germany, France, the UK and the USA at launch, from
official national tables and the European ECA/EFIS data. IARU
amateur band plans included. Auto-detects your region, or set it
manually.
— BUILT FOR FIELD USE —
Fully offline once your library is downloaded. Dark theme with an
optional red night mode. Monospace numerics throughout. Density
over whitespace — the numbers stay on screen.
— WHAT THIS ISN'T —
Bandline is an instrument and a reference, not a receiver. It does
not connect to SDR hardware; it works alongside whatever radio you
already own.
It identifies signal types, never message content. No decryption,
no descrambling, no guidance on intercepting protected
communications — by design, permanently.
— PRO —
One-time purchase, no subscription, ever. Removes ads, unlocks all
offline packs, plus unlimited saved captures, waterfall export and
a private custom signal library.
Signal reference informed by the community work at sigidwiki.com.
Corrections welcome from every card.
Show more
What's New in Bandline
1.0
September 11, 2026





