Glass is not porous so most glues are quite easily removed from glass. If there a small amount it can often be scraped off with a razor or similar edge. If the glass is flat, use a straight surface like the edge of an Exacto knife blade. This will help prevent scratching.
If you have purchased a vase or something similar and are trying to remove the glue from the sticker usually just rubbing your finger over it will do. If it is a bit tougher than this try a bit of oil. Just about any oil will do – you can use something like WD-40 if you like. Work a drop into the residue and it should help lift it.
If any type of glue has just been spilled and is still wet (other than super glue), use a paper towel to soak up as much as you can. If you ‘wipe’ it will likely smear so ‘dab’ the glue with the paper towel.
If there is a lot spilled then some sort of solvent needs to be used to soften the glue. If you can get most of it off this way you can then scrape the remainder as above.
Something like craft glue should wash off fairly easily with water or soap and water.
A slightly tougher glue like carpenter’s glue or white glue, can often be soaked in warm water to soften and then be peeled off.
For an epoxy, peel off as much as you can then scrape or soften with a solvent such as paint thinner or turpentine(be very careful with these – follow the instructions, please!) – you can even try acetone if you have some. Rarely will these things damage the glass. (But do test if you can.) Place a little solvent on the glue and let it soak in. If there is a lot and you want to let is soak in for a bit, place a bit of cling wrap(Saran Wrap) over after you have applied the solvent to keep it from evaporating.
You can also try Mister Glue’s Un-cure. This is mostly used for super glue type adhesives and occasionally works with other glue.
Start simple when you are removing glue from glass. You are more likely to break the glass with using too heavy a scraper than you are damaging from a solvent.
Once you have gently scraped off most of the residue you can apply a bit of isopropyl alcohol (rubbing alcohol) for the final clean up.
If your glass is attached to something where the solvent could spill or leak into or onto an undesired place you can try cold. Put some ice against the glue to make it brittle. Then peel it off.
Most of these techniques will work on any glazed finish: ceramics and porcelain.
If you are dealing with super glue (krazy glue, cyanoacrylate glue) and need something to remove it, then please check out our Super glue section.