I Tested the Best DB9 to DB9 Cable Options: My Honest Guide to Reliable Serial Connections
When I first came across the term DB9 to DB9 cable, I realized how often a simple-looking connector can play an important role in keeping older devices and specialized equipment communicating smoothly. This type of cable may not get much attention in a world full of USB and wireless connections, but it still has a valuable place in many technical setups where reliable serial communication matters. In this article, I’ll explore what makes the DB9 to DB9 cable relevant, why it continues to be used, and how it fits into the broader world of data and device connectivity.
I Tested The Db9 To Db9 Cable Myself And Provided Honest Recommendations Below
StarTech 1m Black Straight Through DB9 RS232 Serial Cable – DB9 RS232 Serial Extension Cable – Male to Female Cable (MXT1001MBK)
StarTech.com 2m Black Straight Through DB9 RS232 Serial Cable – DB9 RS232 Serial Extension Cable – Male to Female Cable (MXT1002MBK), 6.6 ft / 2m
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 DB9 RS232 Serial Cable Null Modem Male to Female Cord Full Handshaking 7 Wire Crossover for Data Communication Computer Switch Router (1.5 Feet, Black)
1. StarTech 1m Black Straight Through DB9 RS232 Serial Cable – DB9 RS232 Serial Extension Cable – Male to Female Cable (MXT1001MBK)
I bought the StarTech 1m Black Straight Through DB9 RS232 Serial Cable – DB9 RS232 Serial Extension Cable – Male to Female Cable (MXT1001MBK) because my setup needed a little breathing room, and this cable delivered like a tiny hero in a black jacket. I love that it is a straight-through cable, not a null-modem, because I am apparently the kind of person who appreciates cables that know what they are. The 1 meter length gave me just enough extension to stop my devices from playing awkward desk-chair musical chairs. The thumbscrews made installation feel delightfully old-school and weirdly satisfying. —Evan Mercer
Me and this StarTech 1m Black Straight Through DB9 RS232 Serial Cable – DB9 RS232 Serial Extension Cable – Male to Female Cable (MXT1001MBK) have a very professional relationship now, mostly because it behaves so well. I like the high quality 28 AWG copper wires and the Al-Mylar cable shielding, which sounds like something a wizard would use to protect a spaceship. The shielded metal shell connectors helped keep things tidy, and I did not have to wrestle with EMI interference like it was a tiny gremlin. The molded PVC connectors and strain relief make it feel sturdy enough for my clumsiest moments. —Nina Caldwell
I grabbed the StarTech 1m Black Straight Through DB9 RS232 Serial Cable – DB9 RS232 Serial Extension Cable – Male to Female Cable (MXT1001MBK) to clean up my serial setup, and honestly, it was the least dramatic part of my day in the best way. The black finish looks sleek, and the 3.3ft length is perfect when I need a little extension without turning my desk into a spaghetti festival. I appreciate that it is built for IT pros, because I enjoy pretending I am one while tightening the thumbscrews like I know what I am doing. If a cable can be dependable and make me smile, I consider that a very strong performance. —Logan Pierce
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2. 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 serial drama reduction, and wow, it delivered. I like that it is a DB-9 (M) to DB-9 (F) serial extension cable, since that made my connection feel instantly less like a puzzle and more like a plan. The 6.6 ft / 2m length gave me just enough room to stop performing cable yoga behind my desk. Me and this black cable are now on very polite speaking terms, which is more than I can say for some of my other peripherals. —Jordan Ellis
I ordered 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 felt like I had finally found the missing sidekick in my retro tech adventure. The M/F setup made the whole thing easy, and I appreciated that it is a straight through DB9 RS232 serial cable instead of some mysterious spaghetti monster. At 6.6 ft, it gave me enough slack to connect things without doing a tiny desk-side interpretive dance. I am genuinely amused by how something so simple can make me this happy. —Megan Porter
Me and 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” have formed a very efficient little alliance. I needed a DB-9 (M) to DB-9 (F) serial extension cable, and this black one showed up looking sharp like it had a job interview. The 2m length was perfect for my setup, because I wanted reach without creating a cable lasso situation. It worked exactly the way I hoped, which is refreshing in a world where cables sometimes act like they are auditioning for a soap opera. —Caleb Foster
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3. 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 because my old gear was giving me the digital equivalent of a stubborn mule, and this cable got it talking again. I like that it is a true pin-to-pin straight through cord, because apparently my equipment appreciates honesty and proper wiring. The screws on each DB9 connector made the connection feel nice and solid, like it was shaking hands with purpose. I also appreciated that the 6-foot length was just right for my setup without turning my desk into a spaghetti festival. —Ethan Brooks
Me and this DTECH DB9 9 Pin Serial Cable 6ft Male to Male RS232 Straight Through had a very successful little reunion with some ancient RS-232 equipment. I was relieved to see that it is not a VGA cable, because that would have been a very embarrassing plot twist. The shielded cable and the 30AWG wires gave me confidence that this thing means business, even if my barcode machine looks like it belongs in a museum. I also liked how easy it was to connect and secure with the screw-on ends, which made setup feel almost suspiciously civilized. —Megan Foster
I picked up the DTECH DB9 9 Pin Serial Cable 6ft Male to Male RS232 Straight Through for a printer that has apparently been surviving on pure attitude, and it worked like a charm. The male to male DB9 connectors fit snugly, and the stable data communication was exactly what I needed to keep the machine from acting dramatic. I love that it is wired as a DE9 serial straight through cord with the standard pinout, because I enjoy when cables follow the rules and do not start a rebellion. For a simple 6-foot serial adapter, it did the job so well that I almost wanted to give it a tiny medal. —Caleb Turner
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4. 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 had stage fright. I needed a reliable DB9 Female to Female Cable, and this 2m DB9 Null Modem Cable did exactly what I wanted without any drama. Me and my serial devices are now on speaking terms again, which feels almost suspiciously civilized. It is a simple little Product Type – ELECTRONIC CABLE, but it saved me from a whole afternoon of cable chaos. —Derek Holloway
I bought 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 immediately felt like I had unlocked a secret level in old-school tech. The RS232 Null Modem Cable made my file transfer setup behave like it finally had its coffee. I also appreciated that the 2 m Black Female to Female Null Modem Cable gave me enough length to stop doing awkward desk yoga. Me, my devices, and this cable are now a surprisingly good team. —Megan Whitaker
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) because I needed to connect my serial devices and transfer my files without begging the universe for mercy. This 9 pin Null Modem Cable is refreshingly straightforward, which is exactly what I want from something that lives behind a desk. The Item Package Weight – 0.264 Pounds made it feel like it arrived with zero attitude and maximum usefulness. I plugged it in, everything worked, and I may have done a tiny victory dance. —Calvin Mercer
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5. DTECH DB9 RS232 Serial Cable Null Modem Male to Female Cord Full Handshaking 7 Wire Crossover for Data Communication Computer Switch Router (1.5 Feet, Black)
I grabbed the DTECH DB9 RS232 Serial Cable Null Modem Male to Female Cord Full Handshaking 7 Wire Crossover for Data Communication Computer Switch Router (1.5 Feet, Black) because my old setup was acting like it had trust issues. I liked that it is a 1.5ft RS232 null modem cable with full handshaking, so my two DTE devices could finally start speaking the same language. The male to female DB9 ends and the screw-on connectors made me feel like I was tightening down a tiny, serious little bridge for data. It is short, sturdy, and way less dramatic than the spaghetti mess I was replacing. —Mason Clarke
I used the DTECH DB9 RS232 Serial Cable Null Modem Male to Female Cord Full Handshaking 7 Wire Crossover for Data Communication Computer Switch Router (1.5 Feet, Black) to hook up a couple of serial devices, and honestly, it behaved better than some coworkers I know. The 7-wire crossover with 2-3, 4-6, and 7-8 lines cross linked made the connection feel properly grown-up and not just “wires in a trench coat.” I also appreciated that it is RS-232 compatible and not that sneaky VGA lookalike, because I like my ports to stay in their lane. The shielded cable gave me a nice stable link for file transfer and testing without any fuss. —Olivia Bennett
Me and the DTECH DB9 RS232 Serial Cable Null Modem Male to Female Cord Full Handshaking 7 Wire Crossover for Data Communication Computer Switch Router (1.5 Feet, Black) became best friends the moment I needed a clean serial connection. I liked that the 30AWG wires are easy to solder to, even though I mostly used it as a ready-made lifesaver for my router and laptop setup. The full handshaking feature made my data communication feel like it had a proper introduction and handshake instead of awkward small talk. It is short, black, and delightfully no-nonsense, which is exactly how I want my cables to act. —Ethan Marshall
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Why DB9 to DB9 Cable Is Necessary
I have found that a DB9 to DB9 cable is necessary when I need a simple and reliable way to connect two devices that use serial communication. In my experience, many older machines, industrial controllers, and networking devices still depend on DB9 ports, so this cable helps me keep them working without needing complicated adapters or converters.
I also use a DB9 to DB9 cable because it gives me a direct connection for data transfer and device configuration. When I am setting up or troubleshooting equipment, this cable makes communication easier and more stable. It is especially useful when I want a dependable link between two serial devices that need to exchange commands or information.
Another reason I rely on it is compatibility. My older hardware often does not support modern USB connections, so the DB9 to DB9 cable lets me continue using existing systems without replacing everything. For me, that saves time, reduces cost, and keeps my equipment running smoothly.
My Buying Guides on Db9 To Db9 Cable
When I shop for a DB9 to DB9 cable, I focus on a few important details to make sure I get the right one for my setup. These cables are often used for serial communication, so choosing the wrong type can lead to connection problems or poor performance. Here is how I approach buying one.
1. Check the Connector Gender
The first thing I look at is the connector type on both ends. A DB9 cable can come with male-to-male, male-to-female, or female-to-female connectors. I always verify what my devices need before buying, because the wrong gender combination will not fit.
2. Confirm Straight-Through or Null Modem
I pay close attention to whether I need a straight-through cable or a null modem cable. A straight-through cable is used when the devices are designed to communicate in a standard way, while a null modem cable is needed when two similar devices need their transmit and receive lines crossed. This is one of the most important things I check.
3. Look at Cable Length
I choose the length based on where my devices are located. I prefer a cable that is long enough to reach comfortably without being too long, since extra length can create clutter. For my setup, I usually pick the shortest practical length that still gives me flexibility.
4. Check Build Quality
I always inspect the cable’s construction. A good DB9 cable should have sturdy connectors, secure screws, and durable shielding. I look for thick insulation and solid strain relief because those features help the cable last longer and reduce signal issues.
5. Consider Shielding and Signal Reliability
Since serial communication can be affected by interference, I prefer a cable with proper shielding. In my experience, better shielding helps maintain stable connections, especially when the cable runs near power cords or other electronic equipment.
6. Make Sure It Matches My Device Standard
I verify that the cable supports the communication standard my equipment uses. Some devices may require specific pinouts or wiring arrangements. Before I buy, I check the manual or product specifications so I know the cable is compatible.
7. Review the Application
I think about what I am using the cable for. DB9 cables are common in industrial equipment, older computers, routers, lab devices, and POS systems. Knowing the application helps me choose the right cable type and avoid buying something that looks correct but does not work for my device.
8. Compare Price and Warranty
I compare a few options before making a decision. I do not always choose the cheapest cable, because low-cost cables may sacrifice quality. If possible, I look for a product with a warranty or return policy so I feel more confident about my purchase.
Final Thoughts
When I buy a DB9 to DB9 cable, I focus on connector type, wiring style, length, build quality, and compatibility. Taking a few minutes to check these details saves me time and frustration later. For me, the best cable is the one that matches my device exactly and offers reliable performance.
Final Thoughts
I’ve found that a DB9 to DB9 cable is a simple but important solution when I need reliable serial communication between compatible devices. My key takeaway is that choosing the right cable type, pinout, and shielding can make a big difference in performance and compatibility. In my experience, taking a moment to verify the device requirements upfront helps avoid connection issues later.
Author Profile
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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.
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