What's the difference betweeen Lumineers and veneers? What gives the whitest teeth of the two?

Veneers will be far better to give you a whiter smile than lumineers, since lumineers need to be very thin in order to look somewhat descent looking! even that thin amount of porcelain added can make your teeth bulkier!!
With veneers we are creating additional room for porcelain to mask the discoloration!

 I hate that question because anyone can create a toilet bowl white smile.  Your goal should be a full healthy natural looking smile that provides proper lip support and gives you the shade of teeth you desire..  Value is the term that describes whiteness and Chroma describes color.  White is usually pretty awful what you want is a high value or whiteness to appropriate chroma.Imagine having a can of paint and starting to add white paint.  You will get whiter and brighter paint but the underlying chroma will remain the same.I suggest you start with provisional that you wear for a month or two before cement veneers.  Most patients who get "Whitest teeth possible" end up hating the look and replacing them.Smile creation is an art!  Find an artist who has an excellent local lab who can customize veneers.The brand of veneer is not what determines results.  You never want to see a dentist who only utilizes on brand.  Its like working with a contractor who only uses a hammer.  Ira L Shapira DDS, D,ABDSM, D,AAPM, FICCMOChair, Alliance of TMD OrganizationsDiplomat, American Academy of Pain ManagementDiplomat, American Board of Dental Sleep MedicineRegent & Fellow, International College of CranioMandibular OrthopedicsBoard Eligible, American Academy of CranioFacial PainDental Section Editor, Sleep & Health JournalMember, American Equilibration SocietyMember, Academy of Applied Myofunctional Sciences

If veneers are done properly, there is total control over the shape of the final teeth. With Lumineers you are slightly less limited in the way you can shape the final result. That being said, shape is infinitely more important than color. For that reason, a traditional veneer is usually a better option. Once the shape is designed well, getting a white color is the rather easy.
Best, 

Hi:Lumineers requires very little to no preparation of the tooth and veneer requires preparation of the tooth.  In my experience if the teeth are in proper position, lumineers can make the teeth look too wide and too far forward.  However if the teeth need to be built out lumineer is a very good option.  Normally with veneers you can make the teeth much whiter due to having thicker porcelain.Best,Dr. Maddahi

Hello there,
Lumineers and traditional veneers can both get you white teeth.  The major difference is lumineers go over the teeth with little to no tooth preparation whereas veneers require some tooth modification but are much more versatile.  Choosing the right situation is critical for lumineers to look good and appear natural.  If lumineers are done on the wrong type of smile, they can easily appear too big, bulky and or opaque. Traditional veneers have much more flexibility in what they can achieve.
It's also very important to understand how "white" you want your teeth.  Too white will look fake with either lumineers or traditional veneers.  I would recommend closely examining before and after pictures of the doctor's actual patients, checking for color, shape, size, and translucency. Ask to see specific examples of lumineers vs traditional veneers before making any decision of how white to go and which type of veneer. Good luck!