The difference mainly comes down to the opening size - and that small detail changes how you use them.
Wide Mouth Jars
Wide-mouth jars have an opening of about 3 inches (around 86 mm). Because of the larger mouth, it's easier to fill them with chunky foods like pickles, peaches, or whole vegetables. They're also simpler to clean and scoop from, which is why many people prefer them for dry goods or bulk storage.
Another plus is that it's easier to reach inside with your hand or a spoon. So if you're using jars for meal prep, crafts, or packaging, wide-mouth jars are often the more convenient option.
Regular Mouth Jars
Regular mouth jars typically have an opening of about 2.75 inches (around 70 mm). They're slightly narrower, which makes them better for pouring liquids or sauces. The smaller opening also helps hold foods down under liquid - a key factor in canning fruits, jams, and preserves.
Because of their slimmer neck, regular mouth jars are often seen as more "traditional." They're easy to handle, fit standard canning lids, and tend to seal tightly for long-term storage.
Which One Should You Choose?
It depends entirely on what you plan to use them for.
If you're preserving large items like cucumbers, tomatoes, or whole fruits → go with wide wide-mouth.
If you're making jams, jellies, or sauces → regular mouth works better.
For commercial packaging, wide-mouth jars make filling and labeling more efficient.
If you prioritize tight sealing and easy pouring, regular mouth jars win.
In short, neither type is "better" - they're just suited for different purposes. Many professionals actually keep both sizes on hand for flexibility.