The key differences at a glance:
- Strength: PLA is stiffer and snaps suddenly under stress. PETG flexes and can take a hit without shattering.
- Ease of printing: PLA is the easiest filament to print with. PETG is slightly trickier due to stringing, but still very accessible.
- Heat resistance: PLA starts to deform around 55–60°C, while PETG holds up to about 80°C.
- Moisture and outdoor use: PLA is sensitive to moisture and sunlight. PETG is water-resistant and better suited for outdoor use.
- Environment: PLA is made from renewable resources, while PETG is not. However, "biodegradable" is a bit more nuanced than it sounds.
- Price: PLA is usually a bit cheaper, but the difference is small.
Quick choice: PLA or PETG?
Choose PLA if you are printing something decorative, making a prototype for visual inspection, need fine details, or are just starting out with 3D printing and still getting to know your machine. PLA is also perfectly fine for parts that stay indoors and won't be exposed to heat or heavy impact.
Choose PETG if your part is going to be put to real use: housings, clamps, holders, brackets, and anything that needs to withstand impact, heat, or moisture. It’s the logical step up once a print needs to do more than just look good.
Is your print going to be outside in direct sunlight? Then even PETG isn't ideal, and you're better off looking at ASA. Read more about that in the 3 best 3D printing materials for outdoor use.
Still not sure? Use our material selection guide or let us take a look with a free printability check.
The main differences explained
Both are popular, versatile filaments. Still, five factors determine which one is right for your print.
1. Strength and functional use
This is where most of the confusion lies, because "stronger" means something different for each of them. PLA has a higher tensile strength (about 50–60 MPa compared to 45–50 MPa for PETG) and is significantly stiffer.
A PLA part holds up perfectly under static loads, but the problem is that the filament is brittle. If overloaded or hit with a sudden impact, it snaps without warning, sometimes into sharp pieces.
PETG trades some stiffness for toughness. It flexes under pressure and has three to four times the impact resistance. Where PLA shatters, PETG deforms and springs back.
What does that mean for you? A hook holding a static weight on the wall is perfectly fine in PLA. But as soon as that same hook gets bumped occasionally, or the part moves and is under load, PETG is the better choice.
2. Ease of printing
PLA wins by a landslide when it comes to ease of printing, which is exactly why it’s the go-to material for beginners. It prints on virtually any printer, adheres without issues, barely warps, and doesn't require a heated bed or an enclosure. You print at about 190–220°C and it barely has any odor while printing.
PETG is more forgiving to print than many people think, but it does require a bit more attention. It adheres very strongly (sometimes too strongly to the bed), prints at 230–250°C, and is prone to stringing: those fine wisps between parts.
3. Heat resistance
This is often the deciding factor, and the difference is significant. PLA starts to soften around 55–60°C. That sounds high, but a black print behind car glass in the sun can easily reach that.
As a result, a PLA print can deform in a hot car, on a windowsill, or near a heat source, and that deformation is permanent.
PETG holds up to about 80°C, giving it a safety margin of about 20 degrees more. For anything that gets near heat, PETG is the safe choice.
4. Moisture and outdoor resistance
PLA absorbs moisture and is sensitive to prolonged exposure to sun and weather. You won't notice much in the short term, but outdoors, a PLA print will weaken and discolor over time.
PETG is water-repellent and resistant to more weather conditions, making it the better choice for parts that get wet or stay outside. If UV radiation is less of a concern and it's mainly about moisture, check out our article on waterproof printing.
5. Environment and biodegradability
PLA is made from renewable resources like corn starch and is therefore often called "biodegradable."
That’s true, but with an important caveat: PLA only breaks down under industrial composting conditions, with high temperatures you won't reach at home or in nature. So, a PLA print won't just disappear in your garden or the regular trash. It is renewable in origin, not something that vanishes on its own.
PETG is not made from renewable resources, but it is recyclable, similar to the PET used in drink bottles. In terms of origin, PLA has better green credentials, but in the waste phase, they differ less in practice than the term "biodegradable" might suggest.
Frequently asked questions about PLA and PETG
Is PLA or PETG stronger?
It depends on the type of strength you need. PLA has higher tensile strength and is stiffer, so it holds up better under a constant load. PETG is tougher and handles impacts or knocks much better without breaking. For static loads, PLA is fine, but for parts that might take a hit, PETG is the winner.
Is PETG harder to print than PLA?
Yes, slightly. PLA is the easiest filament to print, making it ideal for beginners. PETG requires slightly higher temperatures and is prone to stringing, but with the right settings, it’s perfectly manageable, even if you don't have much experience yet.
Can I print PETG on a printer that prints PLA?
Almost always. Most printers that can handle PLA can also print PETG. You just need to increase the nozzle temperature by about 30–40°C and set the heated bed a bit higher. Keep an eye on your retraction settings to minimize stringing.
Is PLA actually biodegradable?
Only partially. PLA is made from renewable resources and is compostable, but only under industrial conditions with high temperatures. It won't break down on its own in your garden or the regular trash. So, while it's more eco-friendly in its origin, it’s not something that just disappears on its own.
Which filament is better for outdoor use?
PETG. It’s water-resistant and holds up better against the elements than PLA, which tends to weaken and fade outdoors. For long-term outdoor use in direct sunlight, ASA is even better than PETG.
Get your part printed in PLA or PETG
Know which material you want? Upload your STL file to our 3D print price calculator and get an instant quote. Both PLA and PETG are available.
Don't have a file yet, or need advice on the right material for your project? Request a free printability check and we'll take a look with you.
