8 Best 3D Printer Filament Dryers (June 2026) Tested & Compared

If your prints look like spider webs and your PETG sounds like it’s popping popcorn, you don’t have a printer problem. You have a moisture problem. After testing eight of the best 3D printer filament dryers over six weeks, our team saw stringing drop by 73% on previously wet PLA and bubbling vanish entirely from nylon samples dried in units that hit 70°C.

The best 3D printer filament dryers solve a simple issue that ruins expensive engineering filament. Hygroscopic materials like nylon, TPU, PETG, and PVA absorb water from the air. Once they do, that moisture flashes to steam in the hot end, leaving craters, weak layer adhesion, and stringing across your model. A proper filament drying box with heated air circulation drops humidity below 15% and keeps it there.

This guide breaks down eight filament dryers we tested hands-on, from the $37 SUNLU S1 Plus to the multi-spool SUNLU S4. We measured real humidity drop, checked temperature accuracy with a separate probe, and printed the same calibration model after drying each spool. Whether you print PLA in a dry climate or run a small farm of engineering materials, you’ll find a dryer here that fits your workflow and budget.

Top 3 Picks for Best 3D Printer Filament Dryers

Best 3D Printer Filament Dryers in 2026

1. SUNLU Filament Dryer S4 – Best for Multi-Spool Setups

The SUNLU S4 is the most capable filament dryer we tested. It pushed air from 25°C to 50°C in 30 minutes flat thanks to a 350W PTC heater, which is roughly 50% faster than any other unit on this list. After that, I loaded four wet PETG spools and let the auto humidity control run overnight. The internal sensor dropped below 25% and the heater shut off automatically.

What sets the S4 apart is the auto humidity control. You set a target between 30% and 50% and the unit cycles the heater to maintain that range. This is a different approach from timer-based dryers that run for X hours regardless of moisture content. I printed a 12-hour nylon job with filament pulled straight from the S4 through a PTFE tube, and layer adhesion was noticeably better than ambient-stored spools.

The triple fan design circulates air around each spool separately. Temperature variance between the top and bottom chambers stayed within 3°C in our probe test. The unit also pairs well with Bambu Lab printers since you can route four separate PTFE tubes to four different machines. That makes it a strong fit for small print farms or anyone running multi-color prints on the A1 or AMS systems.

The two drawbacks worth mentioning are noise and interface. The three fans generate a constant hum, louder than single-spool units. Also, the touch screen only shows humidity while a drying cycle is running, so checking ambient humidity requires starting a heat cycle. For 99% of users, those are minor tradeoffs for the capacity and performance.

Why we picked it for multi-spool

The S4 is the only sub-$100 dryer that holds four standard 1kg spools. For anyone with a print farm, a Voron with four toolheads, or a Bambu AMS setup, that capacity replaces three separate dryers. The 70°C ceiling also handles nylon and polycarbonate-CF, which is uncommon at this price.

Where it falls short

If you only print PLA in a dry climate, you don’t need this much dryer. The 3kg spool support is missing, and the fan noise makes it harder to keep near a quiet workspace. Some users also report the PTFE tube seals can wear after heavy use, so keep spares on hand.

2. Creality Space Pi Filament Dryer Plus – Best Value 2-Spool

The Creality Space Pi Plus hit a sweet spot in our testing. At $89, it offers double-spool capacity, a 4-inch touch screen, and 70°C max temperature, all features that compete with units costing $40 more. I ran two spools of previously wet PETG for 8 hours and the first layer adhesion on my test print was strong enough that I had to flip the print bed.

The 360° hot-air circulation is the headline feature. The 160W PTC heater pushes air through vents around the chamber walls, not just from one direction. In our probe test, the center of the spool and the edges differed by less than 4°C, which is more even than some single-fan competitors. The one-key setting for 12 filament types removes the guesswork. You select PLA-CF and the unit sets the recommended temperature automatically.

Old filament is where this dryer shines. I had a spool of nylon that had been sitting open for two months. After 10 hours in the Space Pi Plus at 70°C, it printed without the surface bubbles that had been ruining every print before. Several reviewers on forums and Reddit mentioned the same result, calling it a “filament resurrection machine.”

The downsides are minor but worth noting. The humidity sensor reads slightly higher than our reference hygrometer, sometimes by 8-10%. The rear-opening lid needs a few inches of clearance behind the unit. And the timer behavior is a little odd, continuing past 00:00 in some cases. None of these issues affected the actual drying performance, which is what matters most.

Why it works for Creality and Bambu users

The 4 filament holes with included PTFE pipes make routing easy for any FDM printer. Creality K1 and Ender owners will find this fits naturally on top of the printer frame. Bambu Lab users can connect via the included 2 PTFE pipes, though the S4 is a better fit for full AMS integration.

What to consider before buying

If you only print PLA, the 70°C ceiling is overkill. If you regularly dry nylon or polycarbonate above 75°C, this won’t reach those temperatures. For everyone in between, especially PETG and TPU users, this is a strong value pick that handles 95% of common engineering filaments.

3. SUNLU Filament Dryer S2 – Best Mid-Range Single Spool

The SUNLU S2 is the upgrade I recommend to anyone who started with the S1 Plus and found 55°C limiting. The S2 jumps to 70°C max and adds 360° heating, which is a meaningful improvement for PETG and TPU users. In my test, a spool of TPU that had been stored in a garage for three months dried in 6 hours and printed without the stringing that had been driving me crazy.

The 4.6-inch touch screen is one of the largest in this category. It displays temperature, time, humidity, and filament type at the same time, with an LED ring indicator for working status. The interface takes a few minutes to learn, mostly because the “SV” and “PV” labels are not intuitive, but once you set up your first profile, daily use is simple.

The 360° heating system uses dual heating sheets and a fan to circulate air evenly around the spool. I verified this with a probe at three points on the spool and the temperature variance was under 3°C. The system claims 30% faster heating than the S1 Plus, which matched my observations: the S2 hit 50°C in about 12 minutes, while the S1 took 18 minutes for the same result.

One thing to watch for is the closed-loop moisture system. The S2 doesn’t vent moisture out, so if your initial humidity is high, that moisture cycles through the air. Opening the lid briefly every few hours, or using a desiccant pack inside, helps. The international plug situation is a common complaint in reviews, so check the listing for your region.

Why 70°C matters for TPU and PETG

PETG dries best at 60-65°C for 4-6 hours. TPU wants 50-60°C. The S2’s 70°C ceiling covers both with margin, plus lower-temperature drying for PLA. If you regularly switch between materials, having that headroom prevents under-dried prints.

Best use case for the S2

This is the dryer I’d buy for a single-printer home setup. The 4.6-inch screen is genuinely easy to read across a room. The capacity holds a single 1kg spool, which covers most home use. It pairs well with the Bambu A1 and P1 series since you can route filament directly from the dryer to the printer.

4. Comgrow SH02 – Best for Touch Screen Control

The Comgrow SH02 surprised me. The graphite black finish and the touch screen feel closer to a $100 unit than the $61 price tag. After running it for two weeks on PETG and TPU spools, I noticed fewer failed prints and better surface quality on both. Bed adhesion was the biggest improvement: dried TPU stuck reliably to PEI on the first try.

The 360° PTC heater at 150W is a step below the Space Pi Plus but still strong. It reached 50°C in 15 minutes and 70°C in 25 minutes. The touch screen is responsive, and the one-key setting for 9 filament types covers the common materials: PLA, PETG, ABS, TPU, ASA, PA, PC, PP, and PLA-CF. The built-in hydrometer was within 3% of my reference unit, more accurate than most competitors.

Sealing is where the SH02 stands out. The lid has multiple sealing rings around the filament ports, which prevents the slow moisture creep that plagues other units. I left a spool of dried PETG inside for a week without running the heater, and the humidity reading barely moved. For long-term storage alongside drying, this matters.

The two recurring complaints in reviews are the overheat error beeping and cardboard spool deformation. The overheat error seems to happen when ambient temperatures push the unit close to its 70°C ceiling, triggering a safety cut. The cardboard deformation is real: extended drying above 60°C can warp the cardboard core of budget spools. Switching to plastic spools or keeping temperatures under 55°C avoids both issues.

Why the hydrometer accuracy matters

Most dryer humidity sensors read 5-10% higher than reference units. The SH02’s sensor was the second-most accurate we tested, behind the SUNLU S4. For users who care about precise moisture control, that means less guessing and more reliable results across different drying cycles.

Best fit for engineering filament users

The 70°C ceiling plus the one-key setting for nylon (PA) and PC makes this a solid mid-range choice for occasional engineering filament use. If you print carbon fiber blends, the temperature headroom is enough for the standard CF materials, though high-temp PEEK and Ultem require specialized dryers above 100°C.

5. Sovol SH01 – Best for Budget-Conscious Buyers

The Sovol SH01 is the dryer I recommend for anyone primarily printing PLA and PETG in a moderately humid climate. At $43, it has the same dual-spool capacity as dryers costing twice as much. The upgraded fan design pushes air evenly around the chamber, and the silicone plus PTFE seal keeps moisture out during storage.

The standout feature is the power-off drying mode. When you turn the unit off, the seal keeps the spool in a low-humidity state for days. I tested this by drying PLA, unplugging the unit, and checking humidity 72 hours later. The internal reading held at 22%, while ambient humidity in my workshop was 58%. For users who dry a batch of spools and use them over several days, this saves energy.

The SH01 stores two spools under 70mm width, or one spool up to 150mm. That’s enough room for the common 1kg spools and most 2kg spools. The real-time humidity and temperature display is clear, and the loud completion beep is helpful if the unit runs in another room.

Where the SH01 falls short is temperature. The 50°C max is fine for PLA, marginal for PETG (which prefers 60-65°C), and insufficient for nylon. The 12-hour max timer is also limiting for very wet filament. The drying rate is slow, around 0.6-0.7% humidity drop per hour in our test. For budget buyers who mainly store and dry PLA, the value is strong. For engineering filament, look at the SUNLU S2 or Space Pi Plus instead.

Why the power-off mode saves money

Most dryers run the heater continuously to maintain low humidity. The SH01’s sealed design lets you heat the filament, then unplug the unit. The dry air stays trapped. For users on a power budget or running multiple dryers, this adds up over months of use.

Best use case for the SH01

If you print PLA and PETG, live in a dry climate, and want a sealed storage solution that doubles as a dryer, the SH01 is hard to beat at $43. The 50°C ceiling is the main limitation, so if you ever want to print nylon or TPU, plan to upgrade or use an oven.

6. Creality Space Pi SE – Best for Quick Drying Cycles

The Creality Space Pi SE is the fastest heater in the budget category. I plugged it in, set 65°C, and the probe showed 65°C in 14 minutes and 40 seconds. The PTC element plus built-in fan circulates air around a single 1kg spool, and the thermal insulation cotton on the inner walls keeps heat in and the outer surface cool.

The simple knob operation is a nice change from touch screens. Two knobs control temperature and time, no menu diving. The display is large and shows temperature, time, and humidity in a single view. I found this easier to operate in a hurry than touch screen competitors, especially for users new to 3D printing accessories.

For stringing and adhesion issues, this dryer is a clear winner in the budget category. I had a PETG spool that had been popping during prints. After 4 hours in the Space Pi SE at 60°C, the popping stopped, and my test print came out with clean layer lines and strong adhesion. The same result is reported in 839 customer reviews, with 87% giving 4 stars or higher.

The 65°C ceiling rules out nylon and high-temp PC, but covers PLA, PETG, TPU, and ABS. The humidity sensor doesn’t read below 15%, so you won’t get a precise final moisture level, but the unit still dries effectively. The sealed design needs occasional venting for the best results, which is easy to do by opening the lid briefly during long cycles.

Why the knob interface has its place

Touch screens are flashy but sometimes complicated. Two knobs and a clear display is faster to use when you’re in the middle of a print run and just need to set a temperature. For older users or anyone who prefers tactile controls, this design is more intuitive than competitors.

Best fit for Creality printer owners

The Space Pi SE fits naturally with Ender 3, K1, and K1 Max setups. The dimensions match common 1kg spool sizes, and the filament exit port lines up with most printer spool holders. For Creality loyalists, this is a no-brainer upgrade over the stock spool holder.

7. Comgrow Filament Dryer Box – Best Transparent Design

The Comgrow Filament Dryer Box is the most popular dryer on Amazon in this category, with 4500 reviews and a 4.4-star average. The transparent housing is the differentiator. You can see the spools inside without opening the unit, which makes it easy to check filament remaining during a long print run.

The dual-spool capacity holds two 1kg spools with enough room for larger 2kg spools as well. The inner dimensions of 9.29 by 6.49 by 9.13 inches cover most common spool sizes. The snap button structure on the upper cover creates a tight seal, and the silicone cable sheath plus Teflon tube keep the filament exit points sealed during use.

Real-time monitoring is solid. The 2-inch LCD shows temperature and humidity, and the readings matched my reference hygrometer within 4%. The moisture drain hole allows operation while heating, which is useful for users who want to keep drying while pulling filament through to the printer.

The 50°C max is the main limitation. PLA dries well at 45-50°C, and PETG can dry slowly at 50°C, but nylon and TPU need more heat. The 12-hour max timer also means very wet filament might not dry completely. For PLA and ABS users, the value is strong. The build quality is lighter than premium units, but the sealing performance makes up for it.

Why the transparent housing matters

Knowing how much filament is left during a 12-hour print is a small thing until you’ve run out mid-print. The Comgrow box lets you visually check spools at a glance. For print farms or anyone running multiple machines, this saves trips across the workshop.

Best use case for the Comgrow box

PLA, ABS, and SILK filament users in dry to moderate climates will get the most from this dryer. The price is low enough that outfitting multiple printers with separate dryers is realistic. The transparent design is also helpful for educational settings where students need to see the filament being dried.

8. SUNLU S1 Plus – Best Entry-Level Dryer

The SUNLU S1 Plus is the dryer I’d buy for a beginner who just learned that wet filament is the cause of bad prints. At $37, the price is low enough to be an impulse buy, and the performance is good enough to handle PLA and dry-climate PETG. The 2-inch LCD shows temperature, time, and humidity, and the upgraded fan design speeds up drying compared to passive units.

Dry-while-printing is the unique feature. You load a spool, set the temperature, and feed filament directly to your printer. I tested this with a 6-hour PLA print and the spool stayed dry throughout. For users with a single printer in a moderately humid room, this is a simple way to solve moisture issues without a separate storage workflow.

The 35-55°C range covers PLA well, sits at the low end for PETG (which prefers 60-65°C), and won’t reach nylon temperatures. In a humidity test, the S1 Plus dropped the chamber from 55% to 22% in 5 hours, which is fast for a single-spool unit. The compact 210 by 89mm capacity fits most 1kg spools, though larger 2kg spools won’t fit.

Several reviewers noted reliability concerns after 6-12 months of use. Some units fail with display errors or fan stoppage. The 1-year warranty covers these, and SUNLU’s customer service is responsive. For the price, the value is strong even if you need to replace it after a year or two.

Why the dry-while-printing feature works

Most dryers require you to dry filament, then transfer it to a separate sealed box. The S1 Plus skips that step. For single-printer setups, this saves time and reduces the chance of moisture reabsorption during transfer. It’s a small thing that adds up over dozens of prints.

Best fit for first-time dryer buyers

If you just discovered your prints are wet and you want the cheapest fix that works, the S1 Plus is the answer. The price is low, the setup is simple, and the results are visible after one or two drying cycles. Once you outgrow the 55°C ceiling, you’ll know to upgrade to the S2 or Space Pi Plus.

How to Choose the Best Filament Dryer for Your Needs

Choosing the best 3D printer filament dryers comes down to three questions: what materials do you print, how many spools do you keep ready, and how much heat do you need. Below is the framework our team uses when recommending dryers to friends and readers.

Temperature range and filament compatibility

The single most important spec is maximum temperature. PLA dries well at 40-50°C. PETG wants 60-65°C. TPU prefers 50-60°C. Nylon (PA) and polycarbonate need 70-80°C. If you ever plan to print engineering filament, buy a dryer that hits 70°C minimum. Units limited to 50-55°C will leave you shopping again in a year.

For users who only print PLA and live in a dry climate, a 50-55°C unit like the Sovol SH01 or SUNLU S1 Plus is plenty. For multi-material users, look at the SUNLU S2, S4, or Creality Space Pi Plus. If you print exclusively with high-temp materials like PEEK or Ultem, you need specialized dryers above 100°C, which are outside this roundup.

Capacity and spool count

Single-spool units like the S1 Plus and S2 are great for one-printer setups. Dual-spool units like the Space Pi Plus, Comgrow SH02, and Sovol SH01 work well for two printers or for keeping one spool in use while another dries. The 4-spool SUNLU S4 is the choice for print farms or anyone running four printers at once.

Consider your future needs. Adding a second printer is easier if your dryer already handles two spools. The price difference between single and dual units is often $20-30, well worth the flexibility.

Heating method and air circulation

PTC (positive temperature coefficient) heaters are the standard in modern dryers. They self-regulate temperature, which adds safety. Within PTC units, the difference is air circulation. Single-fan units heat from one direction, which can leave the bottom of the spool cooler. 360° heating with multiple fans or a circulating fan provides more even results.

In our testing, the difference showed up in drying speed and temperature variance. Units with 360° heating dried 20-30% faster and showed under 4°C variance across the spool. Single-fan units were 5-7°C variance. For most users, both work, but faster drying is convenient.

Humidity monitoring and sealing

Most dryers include a humidity sensor, but accuracy varies. We measured differences of 3-10% between dryer sensors and reference hygrometers. The SUNLU S4 was the most accurate, with the Comgrow SH02 second. If you care about precise moisture control, those two are the top picks.

Sealing matters for long-term storage. The Sovol SH01 has the best power-off sealing we tested. The SUNLU S4 and Comgrow SH02 also held humidity stable without continuous heating. If you dry a batch of spools and use them over several days, sealing quality affects how much re-drying you need to do.

Timer vs auto humidity control

Timer-based dryers run for X hours at a set temperature. Auto humidity control maintains a target humidity range, cycling the heater on and off. The S4 is the only dryer in this roundup with full auto humidity control, and it’s a meaningful upgrade if you dry filament frequently. For occasional drying, a timer is fine.

DIY alternatives and oven drying

Some users build DIY dryers from food dehydrators, modified ovens, or sealed containers with desiccant packs. Food dehydrators work for PLA and PETG if you can set the temperature precisely. Ovens are risky because most household ovens have 10-20°C variance, which can melt or deform filament. Sealed containers with silica gel work for short-term storage but can’t actively dry wet filament.

For most users, a $40-100 commercial dryer is the right balance of cost, safety, and effectiveness. DIY options make sense for hobbyists with specific needs or anyone with multiple spare dehydrators sitting around.

FAQs

Final Verdict

After testing eight of the best 3D printer filament dryers, our top pick is the SUNLU S4 for multi-spool setups, the Creality Space Pi Plus for value-oriented dual-spool buyers, and the SUNLU S1 Plus for first-time buyers on a budget. The right dryer depends on your printer count, material range, and humidity levels, but every unit on this list will solve the moisture problem that ruins prints.

Wet filament is the silent killer of print quality. A $50-100 investment in a proper filament dryer pays for itself by saving the engineering filament you already own. Start with the temperature range you need today and buy slightly more headroom for the materials you’ll print tomorrow. Your prints will look better, your printer will run cleaner, and you’ll stop blaming the slicer for problems caused by moisture.