RTL-SDR
Hacker ApprovedSoftware defined radio dongle
Cheap receiver that lets people explore radio signals and serves as a gateway into software defined radio. Caveat: its 8-bit ADC struggles near strong transmitters.
Cheap receiver that lets people explore radio signals and serves as a gateway into software defined radio. Caveat: its 8-bit ADC struggles near strong transmitters.
20 people gave an opinion
- recommend it
- 16
- criticize it
- 4
- approval share
- 80%
Recommended in 5 of 13 months
- November 2025: not recommended
- December 2025: recommended
- January 2026: recommended
- February 2026: not recommended
- March 2026: not recommended
- April 2026: not recommended
- May 2026: not recommended
- June 2026: not recommended
- July 2026: recommended
- August 2026: recommended
- September 2026: not recommended
- October 2026: recommended
- November 2026: not recommended (month in progress)
Why it carries the badge
- 16 people recommend itNeeds 10 or more, met.
- 4 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 5 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Easy entry into radio hobby
“I got this to play around with what's on the air, and now I'm a full blown extra.”
Comment from 15 Jan 2026 in “Ask HN: What are your best purchases under $100?” “The RTLSDR is an easy way to see if you'd like radio or not.”
Comment from 16 Jan 2026 in “Ask HN: What are your best purchases under $100?” “The RTL SDR is the gateway drug into SDR's.”
Comment from 12 Oct 2026 in “Turn a WiFi 7 Router into a 320Msps Software Defined Radio Receiver” - Comment from 16 Jan 2026 in “Ask HN: What are your best purchases under $100?”
Cheap with good value
“Good and cheap is probably still RTL-SDR and HackRF.”
Comment from 13 Oct 2026 in “Turn a WiFi 7 Router into a 320Msps Software Defined Radio Receiver” “running on a cheap RTL-SDR inside my house”
Comment from 4 Oct 2026 in “Federal judge calls Flock 'indiscriminate mass surveillance'” Wide range of hidden signals
“there is so much to see 'hidden' in electromagnetic radio frequency space”
Comment from 15 Dec 2025 in “$5 whale listening hydrophone making workshop” “have a much more interesting frequency range”
Comment from 13 Oct 2026 in “Turn a WiFi 7 Router into a 320Msps Software Defined Radio Receiver” Works with open source software
“Stick an RTL-SDR dongle on your computer and use the program rtl_433 to monitor that traffic.”
Comment from 12 Oct 2026 in “Turn a WiFi 7 Router into a 320Msps Software Defined Radio Receiver” “A RTL-SDR dongle and scipy.signal would handle all that in like 50 lines of code”
Comment from 18 Jan 2026 in “Receiving Natural VLF Radio Signals”
What people warn about
Each mark is one comment
Weak near strong signals
“the RTLSDR hates close strong signals as its 8-Bit ADC doesn't have much dynamic range”
Comment from 10 Oct 2026 in “Eye of Sauron: Long-Range Hidden Spy Camera Detection (2024)” “RTLSDRs only have a 8-Bit ADC that easily drown next to strong transmitters.”
Comment from 1 Oct 2026 in “Various Projects Find Hidden SDR Capabilities in ESP32 Microcontrollers”
What people said
21 of the 23 comments that mention it, newest first. Each links to the original comment.
“You need stable clock for the processing algorithms to be happy”
“who knows what crystal they use on the no-name ones”
“Good and cheap is probably still RTL-SDR and HackRF.”
“The rtlblog v4 is recommended but hard to get ahold of now. They receive only but actually work quite well when paired with correct antenna.”
“have a much more interesting frequency range”
“Stick an RTL-SDR dongle on your computer and use the program rtl_433 to monitor that traffic.”
“The RTL SDR is the gateway drug into SDR's.”
“The last huge breakthrough there was the now rather old Rtlsdr project”
“the RTLSDR hates close strong signals as its 8-Bit ADC doesn't have much dynamic range”
“I've been having a blast with a RTL-SDR and Claude”
“running on a cheap RTL-SDR inside my house”
“RTLSDRs only have a 8-Bit ADC that easily drown next to strong transmitters.”
“using a pair of RTL-SDRs for more than a decade at this point”
“You could fit a pi zero and rtl in an enclosure not much larger than the one they've printed.”
“just reinforces the extent to which these devices aren't practical”
“In 2026 it's now $30-$40. A ~4x price increase.”
“A RTL-SDR dongle and scipy.signal would handle all that in like 50 lines of code”
“The RTLSDR is an easy way to see if you'd like radio or not.”
“having alot of fun with my new RTL-SDR dongle”
“I got this to play around with what's on the air, and now I'm a full blown extra.”
“there is so much to see 'hidden' in electromagnetic radio frequency space”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.