The Best Borescopes
A borescope puts a camera and lights on the end of a thin probe so you can see inside engines, machinery and anything else you cannot take apart just to look. The right one comes down to the probe's diameter, whether you can steer it or switch its view, and how it shows you the picture. These are the best borescopes across those choices, from a do-it-all dual-lens scope to a 3.9 mm articulating probe for cylinder work.
- 6 picks compared
- Specs checked against maker data
- No paid placements
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- 1For most people, the Teslong NTS500 is the one to buy: a 5.5 mm dual-lens probe with its own 5-inch screen.
- 2If you need to see around corners, such as cylinder walls or the back of a component, an articulating probe is worth the extra cost; the Teslong TF600 steers four ways.
- 3Match the probe to the smallest opening: 3.9 mm clears almost any spark-plug hole, 5.5 mm passes most car plug holes, and 8 mm-class probes suit engine bays and larger openings.
- 1Best overallTeslong NTS500 Dual-Lens Borescope (5.5 mm, 9.8 ft)
- 2Best articulatingTeslong TF600 4-Way Articulating Borescope (6.5 mm, dual lens)
- 3Best two-way articulatingVividia VA-650 Two-Way Articulating Borescope (6.2 mm)
- 4Best for engine cylindersTeslong TF600 3.9mm 4-Way Articulating Borescope
- 5Best valueDEPSTECH DS300 5.5mm Inspection Camera
- 6Best for phonesDEPSTECH NTC55 2K Dual-Lens Borescope
What we recommend
Compare the key specs side by side, then read the full notes on each pick below.
- Probe dia
- 5.5mm
- View
- Front + side
- Display
- 5" screen(1280×720)
- Probe dia
- 6.5mm
- View
- 4-way steering, front + side
- Display
- 6" screen(1080p)
- Probe dia
- 6.2mm
- View
- 2-way steering, up to 180° each way
- Display
- 5"IPS screen
- Probe dia
- 3.9mm
- View
- 4-way steering(360°)
- Display
- 6"IPS screen
- Probe dia
- 5.5mm
- View
- Front
- Display
- 4.3"screen
- Probe dia
- 7.9mm
- View
- Front + side(2K)
- Display
- Phone, wired(USB-C or Lightning)
Teslong NTS500 Dual-Lens Borescope (5.5 mm, 9.8 ft)
Engine bays, machinery and most cylinder checks with one scope
- Probe dia
- 5.5 mm
- View
- Front + side
- Display
- 5" screen (1280×720)
- Front and side cameras, switched with one button
- 5.5 mm probe passes most car spark-plug holes
- IP67 probe; 3500 mAh battery, about 4–5 hours
- 9.8 ft cable
- No articulation: you aim the whole probe
- Video records at 1280×720
The scope most people should buy. A 5.5 mm probe passes most car plug holes, a side camera reads cylinder and pipe walls without any steering, and the 5-inch screen means no phone or app.
What it lacks is articulation and reach: the 9.8 ft cable suits engines and walls but is short for drains. Owners also say the controls take some learning.
Based on the maker's specifications and manual and the published reviews linked below, not on our own test of this unit.
Setup, everyday use and what others found
Setup & use · per the maker
- Front and side cameras. Depending on the production run, you switch between them with a button on the probe's connector or a long press of the shutter button.
- Photos save at 1920 × 1080 and video at 1280 × 720 to the included 32 GB card. The 5-inch IPS screen is 1280 × 720.
- Sharpest about 1.2–3.2 in from the front lens and 0.8–2 in from the side lens.
- 6 LEDs on the front lens and 1 on the side, plus a separate 1 W flashlight on the handle.
- Charges over micro-USB. Teslong rates the 3500 mAh battery at 4–5 hours, and it isn't user-replaceable.
- The probe is IP67 (to 1 m for 30 minutes) but not rated for solvents such as gasoline. The handset is IP45: splashes only.
- Teslong says the 5.5 mm dual-lens probe doesn't take the hook, magnet or mirror accessories.
What others found
A Mercedes forum member who used this exact model on an evaporator inspection was impressed by the video quality and said the side camera is what makes it worthwhile. He also reported the unit froze after he switched lenses a few times while recording; the reset button on the back cleared it.
A B&H reviewer hadn't worked out the controls yet and called the manual poor.
A Van's Air Force forum member couldn't at first work out how to turn on the side-looking camera.
Teslong TF600 4-Way Articulating Borescope (6.5 mm, dual lens)
Steering into blind pockets and around corners
- Probe dia
- 6.5 mm
- View
- 4-way steering, front + side
- Display
- 6" screen (1080p)
- Joystick steering: 360° rotation and 210° bend
- Front and side cameras with 6+1 LEDs
- 6" 1920×1080 IPS screen, 6000 mAh battery
- 32 GB card; mic and speaker for voice notes
- Thicker 6.5 mm probe; the 3.9 mm TF600 slips into small openings more easily
- Costs more than a fixed-probe scope
The pick when you need to steer around corners. Four-way joystick steering with a lock, a side camera and split-screen on a 6-inch screen make it the most capable scope on this page.
It's thicker than the 3.9 mm TF600 at 6.5 mm, leaving less room to steer inside small holes.
Based on the maker's specifications and manual and the published reviews linked below, not on our own test of this unit.
Setup, everyday use and what others found
Setup & use · per the maker
- A joystick steers the tip four ways and can lock it in position. Center it and let the bending section straighten before you withdraw the probe.
- Front camera with 6 LEDs and a side camera with 1, each 1.0 MP, with split-screen viewing. Photos and video save at up to 1920 × 1080 to the included 32 GB card.
- 6-inch 1920 × 1080 IPS screen, plus a built-in microphone and speaker.
- Charges over USB-C. B&H lists about 4 hours to charge the 6000 mAh battery and up to 4 hours of use.
- The 1.55 m probe is IP67; B&H rates the unit for 0–45 °C (32–113 °F). Teslong says the probe can't be replaced if it's damaged.
- In the box: 32 GB card, USB-C cable, hook and magnet tips and a carrying case.
What others found
We found no independent hands-on test and no owner reviews outside Amazon. B&H no longer lists this dual-lens version, and Teslong's own store now sells the F6 PRO as its four-way dual-lens model.
Vividia VA-650 Two-Way Articulating Borescope (6.2 mm)
A compact steerable scope for machinery and engine work
- Probe dia
- 6.2 mm
- View
- 2-way steering, up to 180° each way
- Display
- 5" IPS screen
- Tip steers up to 180° in each direction
- Photos and video at 1280×720
- IP67 camera head on a 1 m flexible metal tube
- 3000 mAh battery; 70° field of view
- Short 1 m (3.3 ft) probe
- Fixed focus, about 15–100 mm from the lens
A compact two-way steerable scope with its own 5-inch screen. The 6.2 mm tip bends up to 180° each way, enough to look back toward the entry point or around most obstructions.
Its limits are resolution and reach: 720p images and a 1 m probe. It's a machinery and engine-bay tool, not a drain camera.
Based on the maker's specifications and manual and the published reviews linked below, not on our own test of this unit.
Setup, everyday use and what others found
Setup & use · per the maker
- A dial bends the tip two ways; Vividia lists up to 180° in each direction. Return the dial to neutral before you withdraw the probe, and don't force it.
- Photos (JPG) and video (MP4, 30 fps) at 1280 × 720, shown on a 5-inch IPS screen.
- Fixed focus, sharpest from about 15 to 100 mm per Vividia, with a 70° field of view and 6 LEDs in three brightness steps.
- USB-C charging at 5 V/1 A with no fast charging; the manual gives about 120 minutes of use from the 3000 mAh battery.
- The camera head is IP67, but the manual says the unit as a whole isn't waterproof and shouldn't be used in liquids. The tube is rated for −10 to 70 °C in air.
- Sellers list a one-year warranty, but the manual says six months, so confirm with the seller.
What others found
We found no independent hands-on test of the VA-650 and no owner reviews outside Amazon.
Teslong TF600 3.9mm 4-Way Articulating Borescope
Cylinder walls, valves and other tight spaces through small openings
- Probe dia
- 3.9 mm
- View
- 4-way steering (360°)
- Display
- 6" IPS screen
- 3.9 mm probe clears almost any spark-plug hole
- 4-way joystick steering (Teslong lists 360°)
- 6-inch IPS screen, LED-lit probe
- 5 ft flexible probe
- Near the top of Teslong's price range
- A fine articulating probe needs a careful hand
The one to buy if cylinder inspection is the main job. The 3.9 mm probe clears 10 mm plug holes, and four-way steering reaches the bore walls and valves from inside.
For general work the NTS500 does more for far less; this is a specialist tool at a specialist price.
Based on the maker's specifications and manual and the published reviews linked below, not on our own test of this unit.
Setup, everyday use and what others found
Setup & use · per the maker
- A joystick steers the tip in four directions; Teslong lists 360° of articulation. Center it and make sure the bending section is straight before you pull the probe out, and never force it.
- Single camera with 6 adjustable LEDs, an 80° field of view and a focus range of about 0.8–3.9 in.
- Saves photos and video at up to 1920 × 1080 to the included 32 GB microSD card, although Teslong rates the 3.9 mm camera itself at 1.0 megapixel.
- 6-inch 1920 × 1080 IPS screen, with a mini-HDMI port alongside the USB-C charging port and card slot.
- Teslong rates the 6000 mAh battery at up to 3.5 hours of use.
- The 1.55 m (5.08 ft) probe is IP67, to 1 m for 30 minutes; don't submerge the monitor. Teslong says the probe can't be replaced if it's damaged.
- In the box: monitor, probe, 32 GB card, USB-C cable and a carrying case. The hook and magnet tips come only with the 6.5 mm version.
What others found
We found no independent hands-on test of the 3.9 mm TF600 and no owner reviews outside Amazon. Teslong now also sells the F8 PRO, a pricier model with the same listed specs and a longer warranty.
DEPSTECH DS300 5.5mm Inspection Camera
A thin-probe scope with its own screen at a fair price
- Probe dia
- 5.5 mm
- View
- Front
- Display
- 4.3" screen
- 4.3" screen, 1080p photos and video; 32 GB card included
- About 4 hours per charge; IP67 probe on a 16.5 ft semi-rigid cable
- Hook, magnet and side mirror in the box
- No side camera or articulation: the mirror attachment gives a side view
- Diesels and some small engines may need a thinner probe
A simple scope with its own screen, well below the Teslong NTS500's price. The 5.5 mm probe and 16.5 ft semi-rigid cable cover engine bays, walls and drains, and it works straight out of the box with no app.
It only looks straight ahead, and Digital Camera World found its recorded video choppy, so treat it as a live-view tool.
Based on the maker's specifications and manual and the published reviews linked below, not on our own test of this unit.
Setup, everyday use and what others found
Setup & use · per the maker
- Hold the power button for 2 seconds to switch on. One press of the capture button takes a photo; hold it for 2 seconds to start or stop video. There is no zoom.
- Two buttons brighten and dim the 6 LEDs through three levels, and another flips the image 180°.
- Records 1080p video and 2 MP (1920 × 1080) photos to the included 32 GB card.
- DEPSTECH lists the sharpest focus at about 5–10 cm (2–4 in) from the lens.
- Charges over micro-USB. DEPSTECH rates it at about 4 hours per charge; one version of the manual says 2.5–3 hours.
- Only the probe is waterproof (IP67), and the manual warns it is not heat-resistant, so let an engine cool first. Rated to work from 32 to 113 °F (0–45 °C).
- In the box: hook, magnet and side-mirror tips, a protective cap and a USB cable. The 16.5 ft cable is semi-rigid.
What others found
Digital Camera World found the live screen sharp and bright enough to use in daylight, but recorded video looked closer to three frames a second. The reviewer also found the back of the probe can catch as you pull it out, and that the grip favors right-handed use.
One Walmart buyer liked that it works on its own, with no app or phone to pair, and another used it to look inside a piston cylinder.
DEPSTECH NTC55 2K Dual-Lens Borescope
A 2K dual-lens picture on your phone over a cable, with no Wi-Fi pairing
- Probe dia
- 7.9 mm
- View
- Front + side (2K)
- Display
- Phone, wired (USB-C or Lightning)
- 2K image from front and side cameras, switched in the app
- Plugs in (USB-C, with a Lightning adapter): no Wi-Fi pairing
- 8+1 adjustable LEDs, IP67 probe; 16.5 ft cable
- 7.9 mm probe is tight in 12 mm plug holes and may not pass 10 mm ones
- Needs the DEPSTECHCAM app, and the cable ties up the phone's port
The best way here to use your phone as the screen: a cable instead of WiFi, 2K resolution and a side camera, all through one app.
The trade-offs are a 7.9 mm probe that's tight in 12 mm plug holes, a phone tied up while you work, and an app with poor reviews.
Based on the maker's specifications and manual and the published reviews linked below, not on our own test of this unit.
Setup, everyday use and what others found
Setup & use · per the maker
- Plugs into the phone over USB-C, with a Lightning adapter in the box, for iOS 11 or later and Android 9 or later. It works only through the DEPSTECHCAM app, and Android phones need OTG turned on.
- The app switches between the front and side cameras and handles capture, 2× zoom and 90° rotation. It works offline and needs no account.
- Images at up to 2560 × 1440 (2K), with 8 LEDs on the front camera and 1 on the side.
- 7.9 mm probe on a 16.5 ft (5 m) semi-rigid cable, rated IP67, with hook and magnet tips included.
- DEPSTECH offers two years of product support.
What others found
The DEPSTECHCAM app has weak ratings. Reviewers complain about slow switching between cameras and the app not detecting the scope unless it's plugged in before the app opens; one says the hardware is excellent but the Android app is buggy. Those reviews cover all DEPSTECH phone scopes.
This dual-lens NTC55 is new, and we found no independent hands-on test.
- Aeronautics diploma
- Engineering degree
- BAMEC (DGCA)
- QC-trained
- ~2 yrs tool management
Why you should trust us
For much of his over two decades in aviation, SK Kutubuddin's day-to-day work was borescope inspection of turbine and compressor blades, where the probe, the lighting and the method decide whether a defect is found. That is the lens for this page: which scope gets a clear, well-lit view of the right spot, and which features actually help you do that.
We compared borescopes across probe sizes, fixed, dual-lens and articulating designs, and screen and phone displays, and checked every figure against the manufacturer's specifications and the live listing, per our how-we-test method. Where a maker's published spec differs from the listing, we used the maker's. This is a buying guide built on verified specs and inspection experience, not a lab test.
Who this is for
This page is for anyone choosing a borescope for mechanical work: home mechanics, motorcyclists, technicians, machinists and anyone who needs to see inside something without taking it apart.
If your work is mostly in walls, ducts and around the house, our inspection camera picks lean toward trade cameras; for drains and sewer lines, see our pipe inspection cameras.
- Checking cylinders, valves and pistons through a spark-plug hole
- Looking inside engine bays, intakes and machinery
- Finding dropped parts in tight spaces
- Anyone choosing between a fixed and an articulating probe
How we picked
We picked one scope for each common need and verified each spec against the maker's data and the live listing.
- 01
A probe for the opening
We covered 3.9 mm probes for the tightest spark-plug holes through to 7.9 mm probes for engine bays, and listed each diameter.
- 02
A way to see to the side
We favored dual-lens and articulating probes, since a forward-only view down a hole misses the walls, where the evidence usually is.
- 03
A display that suits the job
We included screen scopes and a wired phone scope, and said plainly which is which.
- 04
Specs the maker stands behind
We used maker-published figures and corrected listing claims where they disagreed, such as the Vividia's articulation angle and focus range.
What to know before you buy
Probe diameter comes first
A borescope is only useful if its probe reaches the problem. Measure the smallest opening you need to pass. On a car engine that is usually the spark-plug hole, whose threaded bore is roughly 12.6 mm across for a 14 mm plug, 10.6 mm for a 12 mm plug and 8.9 mm for a 10 mm plug. A 3.9 mm probe clears all of them with room to angle it; 5.5 mm passes most car plug holes; an 8 mm-class probe fits 14 mm holes but is tight in smaller ones.
Away from cylinders, a bigger probe is often better: it carries brighter lights and a larger sensor, and engine bays, intakes and machinery housings have room for it.
Fixed, dual-lens or articulating
A single forward camera shows only what is straight ahead. A dual-lens probe adds a side camera you switch to, which covers most sideways looking without twisting the cable. An articulating probe lets you steer the tip: two-way probes bend in one plane, four-way probes in any direction.
Articulation is worth paying for when the thing you need to see is around a corner, such as a cylinder wall, a valve seat or the back of a casting. For general work, a dual-lens probe is simpler, tougher and cheaper.
Screen, phone or Wi-Fi
A scope with its own screen is quickest to use: switch it on and look. A phone scope costs less and uses the screen you already carry; a wired one, like the DEPSTECH NTC55, avoids the lag and pairing of Wi-Fi models. Our iPhone and Android pages cover phone scopes in more depth.
What the spec sheet does not tell you
Lighting and focus matter more than headline resolution in a dark cavity. Look for adjustable LEDs, and check the focus range: many borescope cameras are sharpest only a few centimeters from the lens. Cable stiffness matters too. A semi-rigid cable holds a bend so you can steer it by shaping it, while a floppy one is hard to aim.
How to use a borescope well
Wipe the lens before you start and keep the tip off surfaces, which smears the lens. Before you go in, note a landmark near the entry point, because the picture rotates as the cable twists. Move slowly, use the side view or steer the tip rather than forcing the cable, and photograph anything suspect so you can compare it later or show it to someone else.
Frequently asked questions
What is the best borescope?
For most people, a thin dual-lens scope with its own screen, such as the Teslong NTS500 (5.5 mm, 5-inch screen). If you need to see around corners, an articulating model such as the Teslong TF600 is the step up.
What size borescope do I need?
Measure the smallest opening. A 3.9 mm probe clears almost any spark-plug hole, 5.5 mm passes most car plug holes, and 8 mm-class probes suit engine bays, intakes and larger openings.
Is an articulating borescope worth it?
Yes, if you need to look around corners, such as at cylinder walls or valve seats. For engine bays, walls and general checks, a dual-lens probe usually does the job for less.
Are borescopes waterproof?
Many probes are rated IP67, which means dust-tight and protected against temporary immersion, up to 1 m for 30 minutes. The rating usually covers the probe, not the screen unit.
What is the difference between a borescope and an inspection camera?
Very little in practice. Inspection camera is the retail name for what is technically a video borescope: a camera on a probe feeding a screen or phone.
Can a borescope see inside an engine without taking it apart?
Yes. Through a spark-plug hole it shows the piston crown, the cylinder walls and, with a side view or articulating tip, the valves. Our engine inspection guide explains how.
How long should a borescope cable be?
Long enough for the longest job you actually do. A few feet is plenty for cylinders and engine bays; longer semi-rigid cables help in machinery, walls and ducts but are harder to aim and to coil away.
Do I need a borescope with a screen?
Not if you are happy using your phone, but a screen scope is quicker and works anywhere. A wired phone scope avoids Wi-Fi lag.
Related reading
- Aeronautics diploma
- Engineering degree
- BAMEC (DGCA)
- QC-trained
- ~2 yrs tool management
SK spent over two decades in aircraft maintenance, working hands-on with aero-engine systems and flight data recorder systems, borescope-inspecting turbine and compressor blades, and spending almost two years in a dedicated tool bay. He holds a diploma in mechanical engineering (aeronautics), an associate degree in science, an engineering degree and a Basic Aircraft Maintenance Engineer's Certificate (BAMEC) from DGCA, and has completed quality-control and aviation fuels & lubricants training. GaugeGrade applies the same inspection, torque and tool-management standards to the tools everyday mechanics, DIYers and trades actually buy.