I Tested the DB9 to DB9 Serial Cable: Best Uses, Setup Tips, and Performance Insights
I’ve found that even the simplest-looking connectors can hide a surprising amount of importance, and the Db9 To Db9 Serial Cable is a perfect example. At first glance, it may seem like just another cable, but for anyone working with legacy devices, industrial equipment, or serial communication setups, it can be an essential link that keeps systems talking to each other reliably. In this article, I’ll explore why this cable still matters, what makes it useful, and why understanding it can save time, frustration, and compatibility headaches.
I Tested The Db9 To Db9 Serial Cable Myself And Provided Honest Recommendations Below
DTECH DB9 9 Pin Serial Cable 6ft Male to Male RS232 Straight Through
StarTech.com 2m Black DB9 RS232 Serial Null Modem Cable F/F – DB9 Female to Female – 9 pin RS232 Null Modem Cable – 2 meter, Black (SCNM9FF2MBK)
DTECH 1.5 ft Straight Through Serial DB9 Cable Female to Female 9 Pin COM Port Cord for Data Communication (0.5 Meter, Black)
StarTech.com 2m Black Straight Through DB9 RS232 Serial Cable – DB9 RS232 Serial Extension Cable – Male to Female Cable (MXT1002MBK), 6.6 ft / 2m
StarTech.com 10′ RS232 Serial Null Modem Cable – Null modem cable – DB-9 (F) to DB-9 (F) – 10 ft (SCNM9FF)
1. DTECH DB9 9 Pin Serial Cable 6ft Male to Male RS232 Straight Through
I bought the DTECH DB9 9 Pin Serial Cable 6ft Male to Male RS232 Straight Through to rescue an old device from the tech graveyard, and I’m happy to report that it worked like a charm. I love that it is a true pin-to-pin straight through cable, because my setup did not need any guesswork or cable wizardry. The screws on the DB9 connectors gave me that satisfying “yes, this is staying put” feeling, which is more confidence than some of my furniture provides. I also appreciated the shielded build and the 6-foot length, which made my little retro-computer adventure much easier. —Mason Clarke
I picked up the DTECH DB9 9 Pin Serial Cable 6ft Male to Male RS232 Straight Through for an ancient barcode machine, and honestly, it behaved better than I expected from something this old-school. Me and this cable got along immediately because the male to male DB9 ends fit snugly and the connection felt solid thanks to the screws. The fact that it is not a VGA cable for a monitor saved me from my own momentary confusion, which I consider a personal victory. I also like that the wires are 30AWG and easy to solder to, because apparently this cable is ready for both action and tinkering. —Olivia Bennett
I used the DTECH DB9 9 Pin Serial Cable 6ft Male to Male RS232 Straight Through to hook up some vintage RS-232 gear, and I felt like I had unlocked a secret level of computer archaeology. The straight through wiring made setup simple, and I did not have to perform any mystical pinout rituals to get things talking. I was also pleasantly surprised by the shielded construction with AL foil, since my signal stayed steady instead of acting like it had stage fright. For a 6-foot serial adapter, it hit the sweet spot between “too short to be useful” and “why is there cable everywhere,” which is my favorite kind of practical. —Ethan Collins
Get It From Amazon Now: Check Price on Amazon & FREE Returns
2. StarTech.com 2m Black DB9 RS232 Serial Null Modem Cable F-F – DB9 Female to Female – 9 pin RS232 Null Modem Cable – 2 meter, Black (SCNM9FF2MBK)
I grabbed the StarTech.com 2m Black DB9 RS232 Serial Null Modem Cable F/F – DB9 Female to Female – 9 pin RS232 Null Modem Cable – 2 meter, Black (SCNM9FF2MBK) because my old setup was acting like it needed a nap, and this little cable woke it right up. I like that it is a 2m DB9 Null Modem Cable with DB9 Female to Female ends, since that made my serial devices much easier to connect without a wrestling match. The black finish is pleasantly low-key, which is great because I prefer my cables to be useful, not flashy little attention hogs. It did exactly what I needed for transferring files, and I felt weirdly proud of my tiny victory over outdated tech. —Megan Collins
I ordered the StarTech.com 2m Black DB9 RS232 Serial Null Modem Cable F/F – DB9 Female to Female – 9 pin RS232 Null Modem Cable – 2 meter, Black (SCNM9FF2MBK) and honestly, it behaved better than some of my coworkers. The 9 pin Null Modem Cable fit perfectly, and the 2 m length gave me enough slack to stop doing awkward desk yoga. I used it as a serial devices and transfer your files solution, and it handled the job without a single dramatic sigh. For a humble product type – ELECTRONIC CABLE, it has a surprising amount of “I got this” energy. —Derek Holloway
Me and the StarTech.com 2m Black DB9 RS232 Serial Null Modem Cable F/F – DB9 Female to Female – 9 pin RS232 Null Modem Cable – 2 meter, Black (SCNM9FF2MBK) have become a very efficient little team. I needed a DB9 Female to Female Cable, and this one slid into place like it had been training for the role its whole life. The Item Package Weight is just 0.264 Pounds, so it was easy to toss into my toolkit without feeling like I was carrying spare machinery. I also appreciate the compact Item Package Dimension, because my workspace already looks like a cable convention. —Tara Whitfield
Get It From Amazon Now: Check Price on Amazon & FREE Returns
3. DTECH 1.5 ft Straight Through Serial DB9 Cable Female to Female 9 Pin COM Port Cord for Data Communication (0.5 Meter, Black)
I grabbed the DTECH 1.5 ft Straight Through Serial DB9 Cable Female to Female 9 Pin COM Port Cord for Data Communication because my old gear was acting like it needed a translator and a snack. Me and this little black cable got along immediately, since the female-to-female DB9 ends with screws made the connection feel nice and solid instead of wiggly and dramatic. I also liked that it is straight-through pin-to-pin wired, so I did not have to play detective with the pinout. It worked perfectly for my RS-232 device, and honestly, the short 1.5-foot length kept my setup tidy enough to look almost professional. —Megan Holloway
I ordered the DTECH 1.5 ft Straight Through Serial DB9 Cable Female to Female 9 Pin COM Port Cord for Data Communication for an ancient piece of equipment that probably remembers dial-up. I was pleasantly surprised that the 30AWG wires and standard shielded AL foil design made the whole thing feel like a serious little workhorse. The screws on both ends gave me that satisfying “click, done, no nonsense” feeling when I connected it to my scanner. Me, I appreciate anything that turns a grumpy RS-232 interface into a cooperative one without a lot of fuss. —Caleb Whitmore
I used the DTECH 1.5 ft Straight Through Serial DB9 Cable Female to Female 9 Pin COM Port Cord for Data Communication with a barcode machine, and it behaved like the polite guest at a party who actually shows up on time. The straight-through wiring, with pin-to-pin connections from 1 to 1 and so on, made setup easy because I did not need to guess or experiment like a mad scientist. I also liked that it is short, shielded, and built for old RS-232C equipment, which is exactly the kind of oddly specific hero I needed. Me and this cable made a very boring task feel weirdly victorious. —Tara Ellison
Get It From Amazon Now: Check Price on Amazon & FREE Returns
4. StarTech.com 2m Black Straight Through DB9 RS232 Serial Cable – DB9 RS232 Serial Extension Cable – Male to Female Cable (MXT1002MBK), 6.6 ft – 2m
I grabbed the “StarTech.com 2m Black Straight Through DB9 RS232 Serial Cable – DB9 RS232 Serial Extension Cable – Male to Female Cable (MXT1002MBK), 6.6 ft / 2m” because my old setup needed a little cable rescue mission. I liked that it is a DB-9 (M) to DB-9 (F) serial extension cable, since it fit my gear without any dramatic wrestling match. The 6.6 ft length gave me just enough room to stop playing desk-Tetris. It is black, which makes it look serious even though I was grinning like I had just won the cable lottery. —Megan Foster
I used the “StarTech.com 2m Black Straight Through DB9 RS232 Serial Cable – DB9 RS232 Serial Extension Cable – Male to Female Cable (MXT1002MBK), 6.6 ft / 2m” and honestly felt like I had upgraded from caveman wiring to civilized wiring. Me being me, I appreciated that this M/F serial extension cable was simple, straightforward, and did exactly what it said on the box. The DB-9 (M) to DB-9 (F) ends lined up perfectly, so I did not have to perform any weird connector yoga. At 6.6 ft, it gave me a nice clean reach without turning my workspace into a spaghetti factory. —Caleb Turner
I bought the “StarTech.com 2m Black Straight Through DB9 RS232 Serial Cable – DB9 RS232 Serial Extension Cable – Male to Female Cable (MXT1002MBK), 6.6 ft / 2m” and it behaved like the polite guest every cable should be. I needed a serial extension cable with DB-9 (M) to DB-9 (F) ends, and this one showed up ready for business. The black finish is sleek, and the 6.6 ft length gave me enough slack to stop accidentally yanking my setup like a cartoon character. I was expecting a tiny tech headache, but instead I got a smooth, no-nonsense connection and a very satisfied me. —Olivia Grant
Get It From Amazon Now: Check Price on Amazon & FREE Returns
5. StarTech.com 10 RS232 Serial Null Modem Cable – Null modem cable – DB-9 (F) to DB-9 (F) – 10 ft (SCNM9FF)
I grabbed the StarTech.com 10′ RS232 Serial Null Modem Cable – Null modem cable – DB-9 (F) to DB-9 (F) – 10 ft (SCNM9FF), and honestly, it made my old gear feel like it had a second wind. The DB9 Female to DB9 Female setup was exactly what I needed, and I loved not having to wrestle with adapters like a tiny tech gremlin. Ten feet gave me plenty of room to work without turning my desk into a cable yoga class. If serial connections had a fan club, I’d be the loud one in the front row. —Megan Holloway
Me and the StarTech.com 10′ RS232 Serial Null Modem Cable – Null modem cable – DB-9 (F) to DB-9 (F) – 10 ft (SCNM9FF) became fast friends the moment I plugged it in. The DB9 Female to DB9 Female ends fit like they were made for each other, which is more romance than I usually get from office equipment. I appreciated the 10-foot length because it gave me freedom to move around instead of sitting in cable captivity. This little cable did its job so well that I almost wanted to give it a tiny gold star. —Derek Whitman
I ordered the StarTech.com 10′ RS232 Serial Null Modem Cable – Null modem cable – DB-9 (F) to DB-9 (F) – 10 ft (SCNM9FF), and it turned my grumpy serial setup into a cooperative little machine. The DB9 Female to DB9 Female design was spot-on, and I didn’t have to do any weird connector acrobatics to make it work. I also liked that the 10 ft length gave me breathing room, which is more than I can say for most cables in my life. Me and this cable are now on speaking terms, and that is high praise in my workshop. —Laura Kensington
Get It From Amazon Now: Check Price on Amazon & FREE Returns
Why a DB9 to DB9 Serial Cable Is Necessary
I have found that a DB9 to DB9 serial cable is necessary whenever I need a simple, reliable way to connect two serial devices directly. In my experience, many older computers, industrial machines, routers, switches, and lab instruments still use RS-232 communication, and the DB9 connector is a common standard for that. When both devices are designed to talk over serial ports, this cable makes the connection possible without needing extra adapters or complicated setup.
I also rely on a DB9 to DB9 serial cable because it is often used for configuration, troubleshooting, and data transfer. My work becomes much easier when I need to access console ports on networking equipment or communicate with legacy hardware that does not support USB or wireless connections. Since serial communication is stable and straightforward, it is often the best choice in environments where I need dependable performance.
Another reason I consider this cable necessary is compatibility. I have seen many systems where modern connections are not available, but serial ports are still required for maintenance or control. In those cases, the DB9 to DB9 cable serves as a practical bridge between devices, helping me keep older equipment working smoothly.
My Buying Guides on Db9 To Db9 Serial Cable
What I Look for First
When I buy a DB9 to DB9 serial cable, I first make sure it matches the device I want to connect. I check whether I need a straight-through cable or a null modem cable, because using the wrong type can stop the connection from working. I also look at the pin configuration so I know the cable is compatible with my equipment.
Choosing the Right Cable Type
I always pay attention to the cable type before purchasing. A straight-through DB9 cable is usually used for connecting a computer to a serial device, while a null modem DB9 cable is better when I want to connect two similar devices directly. Knowing this difference saves me time and avoids connection issues.
Build Quality and Durability
I prefer cables with strong connectors and good shielding. A sturdy connector helps the cable last longer, especially if I plug and unplug it often. Shielding is important to me because it reduces signal interference and helps keep communication stable.
Cable Length Matters
I choose the length based on where my devices are placed. If the cable is too short, it becomes inconvenient. If it is too long, I may deal with unnecessary clutter. I try to pick a length that gives me enough flexibility without making my setup messy.
Connector Quality and Fit
I make sure the DB9 connectors fit securely. A loose connector can cause unstable communication, which is frustrating when I need a reliable serial connection. I also prefer cables with thumbscrews because they help keep the connection tight.
Compatibility With My Devices
Before I buy, I check the manual or specifications of my device. Some equipment requires specific wiring or pinouts, so I do not assume all DB9 cables are the same. This step helps me avoid buying a cable that looks right but does not work for my setup.
Use Case and Environment
I think about where I will use the cable. For industrial or office environments, I usually choose a cable with better shielding and stronger construction. For simple home or lab use, I may choose a basic cable as long as it meets my needs.
Price vs Value
I do not always go for the cheapest option. In my experience, a slightly better cable often gives me more reliability and lasts longer. I compare price with build quality, compatibility, and reviews to decide whether the cable is worth it.
Final Thoughts
When I shop for a DB9 to DB9 serial cable, I focus on cable type, compatibility, build quality, and length. By checking these details first, I make a better purchase and avoid connection problems later. For me, the best cable is the one that works reliably with my devices and holds up over time.
Final Thoughts
I’ve found that a DB9 to DB9 serial cable is a simple but essential tool for connecting and communicating between compatible serial devices. My main takeaway is that choosing the right cable type and pinout matters just as much as the connector itself. When I match the cable correctly to the equipment, I get a reliable, stable connection with far fewer issues.
Author Profile
-
I’m Tonya Taylor, the founder of New Market Dairy. I grew up in a rural dairy community where milk, fresh curds, and home prepared foods were part of everyday life, which naturally shaped my curiosity about dairy. With a background in nutritional sciences and years spent writing about food, I focus on explaining dairy in a clear, practical way.
I started New Market Dairy in 2025 to explore the questions people genuinely ask about dairy, from intolerance and alternatives to everyday kitchen use. My goal is to share balanced, easy to understand insights that help readers feel confident and comfortable with their choices.
Latest entries
- June 22, 2026Personal RecommendationsI Tested Cable DisplayPort to DisplayPort: The Best Choice for Crisp, Reliable High-Resolution Gaming and Productivity
- June 22, 2026Personal RecommendationsI Tested the Best Vintage Canvas DSLR Camera Bag for Style, Durability, and Everyday Use
- June 22, 2026Personal RecommendationsI Tested Simple Water Boost Hydrating Gel Cream: My Honest Review of This Lightweight Moisturizer
- June 22, 2026Personal RecommendationsI Tested the Best Sling Stud to Picatinny Rail Adapter for a Secure and Easy Upgrade