Can You Microwave Glass? Which Glass Is Microwave Safe, and Which Isn't

Written by Sara Ibrahim. Sara researches home and kitchen products for Cupindy. · Published October 2026 · Last reviewed October 6, 2026

Is glass microwave safe? Most kitchen glass is: you can put glass in the microwave when it is heat-resistant glass made for cooking and the maker marks it for microwave use. When glass does fail in a microwave, it is usually because of a sudden temperature change, an empty dish, an old chip or crack, or metal in the decoration.

How we put this together: we read the FAQs and care pages of Pyrex, Corelle, CorningWare and Anchor Hocking, the USDA and FDA microwave guidance, and the Amazon listings below (checked with a US delivery address on October 6, 2026). Every quote was checked twice, word for word. We have not tested these products ourselves. The photos show typical kitchen scenes; they are not test results.

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Which glass is microwave safe?

Kitchen glass comes in a few types. This is how each one does in the microwave, with the source for each answer.

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Why glass usually stays cool, and when it doesn't

In the FDA's words: “Glass, paper, ceramic, or plastic containers are used in microwave cooking because microwaves pass through these materials.” The microwaves heat the food, and the food warms the glass.

It also explains the two situations both Pyrex and Corelle warn about:

• An empty dish. Pyrex: “DO NOT heat a tiny amount of food or an empty dish in the microwave.” Corelle says an empty dish “may become too hot to handle, crack or break.”
• A little food in a big dish. Corelle: “DO NOT heat a small amount of food in larger dish in a microwave oven.” Use a dish that fits the portion.

Corelle also recommends a dry pot holder whenever you take its dishes out of a microwave.

How to tell if your glass is microwave safe

• Look for the mark. Check the bottom of the dish for the word microwave or the wavy-lines symbol. Our microwave-safe symbol guide shows every version in pictures.
• Check the box or the maker's website. The USDA says glass that is safe to use will usually be labeled for microwave use.
• Still no answer? Use your microwave's own test. The FDA says the instructions that come with each microwave “cover how to test containers”. Most describe heating the empty dish next to a cup of water for a short time and checking which one got hot.

The test cannot clear decorated glass: anything with metallic paint stays out whatever the test shows.

Can glass break or explode in the microwave?

Yes, and almost always for one of three reasons:

• A sudden change in temperature. Glass cracks when one part of it is much hotter than another. Corelle's rule: “AVOID SUDDEN TEMPERATURE CHANGES. DO NOT add liquid to a hot item, place a hot item on a wet surface, or handle with a wet or cold cloth.” Anchor Hocking says the same: never place hot glass on a wet or cold surface.
• An empty or nearly empty dish, as above.
• Damage you can already see. A chip or crack is where the break starts.

The glass type matters too. Pyrex's FAQ explains the trade-off: “Soda lime is slightly more resistant to impact breakage than borosilicate, and borosilicate is slightly more resistant to extreme thermal changes than soda lime.” Our glass vs plastic containers guide has the numbers behind that, and why some glass shatters while other glass just cracks.

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Can cold glass go in the microwave? Fridge and freezer

Pyrex is clearest about this one. Asked whether a dish can go straight from the fridge or freezer into the oven or microwave, it answers: “Please allow the dish to come to room temperature before inserting into a preheated oven or microwave.” For frozen dishes headed to the oven it adds: “we advise allowing your frozen dish to thaw completely”.

In practice:

• Take the container out of the fridge a little while before you heat it.
• Thaw frozen leftovers in the fridge overnight, not in the microwave in their glass container.
• If your container's own box says it can go from freezer to microwave, that maker's rule is the one to follow for that container.

Glass containers with plastic lids

Most glass storage containers come with a plastic lid, and the lid is usually the weak point. Pyrex's rule for its covers: “The cover must be unsealed from the dish and lay off-center to allow steam to escape.” Rubbermaid's listing for Brilliance says the set is “microwave-safe for reheating only with lids unlatched”. And one best-selling glass meal prep set says on its Amazon listing that its glass can go in the microwave, “(Not the lids)”.

In short, check what the box says about the lid, not just the glass. Never microwave a sealed lid, and keep plastic wrap and lids off the food itself. Our own habit, not a maker rule: skip the plastic lid and cover the dish with a microwave-safe plate. More on plastic in is microwaving plastic safe.

Glass bowls, plates and dishes

Are glass bowls microwave safe? A plain glass bowl, plate or casserole dish follows the same rules as a container: marked for microwave use, no metallic trim, no damage. Two bowl-specific points:

• Match the bowl to the portion. A spoonful of sauce in a large bowl is exactly what Corelle tells you not to do.
• Mixing bowls are made for this. Pyrex's Essentials bowls are listed as “freezer, microwave, and dishwasher safe”, so melting butter or reheating soup in one is normal use.

Want lids? Pyrex Sculpted bowls with lids

Glass cups, mugs and drinking glasses

Can you microwave a glass cup? Only if it is marked for the microwave or its maker says so. Drinking glasses are often thinner than cookware and are not always made to take heat, and decorated ones may carry metallic paint. Our guide to drinking glasses covers which glasses are made for hot drinks.

Water is the other risk with a cup. The FDA warns about super-heated water: “Super-heated water (water heated past its boiling temperature) does not appear to be boiling and occurs when water is heated by itself in a clean cup.” A small knock can then make it erupt. The FDA's fix: “Adding substances such as instant coffee or sugar before heating greatly reduces this risk.”

Is Pyrex microwave safe?

Yes. The USDA names Pyrex as heatproof glass that is safe in the microwave, and Pyrex's own FAQ adds the rules:

• Covers unsealed and set off-center, so steam can escape.
• No empty dishes or tiny amounts of food; room temperature before heating.
• Never on the stovetop, under the broiler, in a toaster oven or on a grill.

Which glass is your Pyrex? Pyrex's FAQ explains both soda-lime and borosilicate but does not say which product is which; the two Pyrex listings we checked say “tempered glass”. The full story is in our glass vs plastic guide. For the oven, see is your cookware oven safe.

Is Corelle microwave safe? And CorningWare?

Corelle: yes. Its FAQ says Corelle dinnerware “is microwave safe when used in accordance with the safety and usage Instructions that came with your product”. Its safety page adds the rules quoted above: no empty dishes, no small portion in a large dish, no sudden temperature changes, no damaged pieces.

One thing Corelle's own pages do not agree on is the oven. The FAQ says its glass dinnerware “is not for use in any type of oven”, while its safety page (and the Amazon listing below) say microwave and pre-heated conventional ovens up to 350°F. Check the instructions that came with your set.

CorningWare: yes. The USDA lists glass-ceramic such as Corning Ware as safe, and Corelle Brands' FAQ includes something many people don't expect: “All CorningWare® oven bakeware products (including metallic-banded French White® products) can be used in conventional, convection and microwave ovens as well as in the refrigerator, freezer and dishwasher.” Its stoneware warning still applies: “When heated or cooled too rapidly, stoneware can break.”

What the makers say, side by side

Only what each maker publishes. “Not stated” means we did not find it on the page we read, not that it is allowed.

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Microwave-safe glass containers we would buy

All five are sold or shipped by Amazon and were in stock when we checked. Prices and stock change, so we do not print prices.

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Questions people ask

Keep reading

• Microwave-safe symbol: how to tell if a dish is microwave safe
• Can you microwave styrofoam?
• Is porcelain microwave safe?
• Glass vs plastic food storage containers
• How to reheat food without drying it out