Note: This is out of date, as more words have been added monthly.
2-letter words
AA AB AD AE AG AH AI AL AM AN AR AS AT AW AX AY
BA BE BI BO BY
DA DE DI DO
ED EF EH EL EM EN ER ES ET EX
FA FE FI
GI GO
HA HE HI HM HO
ID IF IN IS IT
JO
KA KI
LA LI LO
MA ME MI MM MO MU MY
NA NE NO NU
OD OE OF OH OI OM ON OP OR OS OW OX OY
PA PE PI
QI
RE
SH SI SO
TA TI TO
UH UM UN UP US UT
WE WO
XI XU
YA YE YO
ZA
3-letter words
AAH AAL AAS ABA ABO ABS ABY ACE ACT ADD ADO ADS ADZ AFF AFT AGA AGE AGO AHA AHI AHS AID AIL AIM AIN AIR AIS AIT ALA ALB ALE ALL ALP ALS ALT AMA AMI AMP AMU ANA AND ANE ANI ANT ANY APE APP APT ARB ARC ARE ARF ARK ARM ARS ART ASH ASK ASP ASS ATE ATT AUK AVA AVE AVO AWA AWE AWL AWN AXE AYE AYS AZO
BAA BAD BAG BAH BAL BAM BAN BAP BAR BAS BAT BAY BED BEE BEG BEL BEN BET BEY BIB BID BIG BIN BIO BIS BIT BIZ BOA BOB BOD BOG BOO BOP BOS BOT BOW BOX BOY BRA BRO BRR BUB BUD BUG BUM BUN BUR BUS BUT BUY BYE BYS
CAB CAD CAM CAN CAP CAR CAT CAW CAY CEE CEL CEP CHI CIS COB COD COG COL CON COO COP COR COS COT COW COX COY COZ CRY CUB CUD CUE CUP CUR CUT CWM
DAB DAD DAG DAH DAK DAL DAM DAP DAW DAY DEB DEE DEF DEL DEN DEV DEW DEX DEY DIB DID DIE DIF DIG DIM DIN DIP DIS DIT DOC DOE DOG DOL DOM DON DOR DOS DOT DOW DRY DUB DUD DUE DUG DUH DUI DUN DUO DUP DUX DYE
EAR EAT EAU EBB ECU EDH EEL EFF EFS EFT EGG EGO EKE ELD ELF ELK ELL ELM ELS EME EMF EMS EMU END ENG ENS EON ERA ERE ERG ERN ERR ERS ESS ETA ETH EVE EWE EYE
FAB FAD FAN FAR FAS FAT FAX FAY FED FEE FEH FEM FEN FER FET FEU FEW FEY FEZ FIB FID FIE FIG FIL FIN FIR FIT FIX FIZ FLU FLY FOB FOE FOG FOH FON FOP FOR FOU FOX FOY FRO FRY FUB FUD FUG FUN FUR
GAB GAD GAE GAG GAL GAM GAN GAP GAR GAS GAT GAY GED GEE GEL GEM GEN GET GEY GHI GIB GID GIE GIG GIN GIP GIT GNU GOA GOB GOD GOO GOR GOT GOX GOY GUL GUM GUN GUT GUV GUY GYM GYP
HAD HAE HAG HAH HAJ HAM HAO HAP HAS HAT HAW HAY HEH HEM HEN HEP HER HES HET HEW HEX HEY HIC HID HIE HIM HIN HIP HIS HIT HMM HOB HOD HOE HOG HON HOP HOT HOW HOY HUB HUE HUG HUH HUM HUN HUP HUT HYP
ICE ICH ICK ICY IDS IFF IFS IGG ILK ILL IMP INK INN INS ION IRE IRK ISM ITS IVY
JAB JAG JAM JAR JAW JAY JEE JET JEU JIB JIG JIN JOB JOE JOG JOT JOW JOY JUG JUN JUS JUT
KAB KAE KAF KAS KAT KAY KEA KED KEF KEG KEN KEP KEX KEY KHI KID KIF KIN KIP KIR KIT KOA KOB KOI KOP KOR KOS KUE KYE
LAB LAC LAD LAG LAM LAP LAR LAS LAT LAV LAW LAX LAY LEA LED LEE LEG LEI LEK LET LEU LEV LEX LEY LEZ LIB LID LIE LIN LIP LIS LIT LOB LOG LOO LOP LOT LOW LOX LUG LUM LUV LUX LYE
MAC MAD MAE MAG MAN MAP MAR MAS MAT MAW MAX MAY MED MEG MEL MEM MEN MET MEW MHO MIB MID MIG MIL MIM MIR MIS MIX MOA MOB MOC MOD MOG MOL MOM MON MOO MOP MOR MOS MOT MOW MUD MUG MUM MUN MUS MUT
NAB NAE NAG NAH NAM NAN NAP NAW NAY NEB NEE NET NEW NIB NIL NIM NIP NIT NIX NOB NOD NOG NOH NOM NOO NOR NOS NOT NOW NTH NUB NUN NUS NUT
OAF OAK OAR OAT OBA OBE OBI OCA ODA ODD ODE ODS OES OFF OFT OHM OHO OHS OIL OKA OKE OLD OLE OMS ONE ONS OOH OOT OPE OPS OPT ORA ORB ORC ORE ORS ORT OSE OUD OUR OUT OVA OWE OWL OWN OXO OXY
PAC PAD PAH PAL PAM PAN PAP PAR PAS PAT PAW PAX PAY PEA PEC PED PEE PEG PEH PEN PEP PER PES PET PEW PHI PHT PIA PIC PIE PIG PIN PIP PIS PIT PIU PIX PLY POD POH POI POL POM POO POP POT POW POX PRO PRY PSI PUB PUD PUG PUL PUN PUP PUR PUS PUT PYA PYE PYX
QAT QIS QUA
RAD RAG RAH RAI RAJ RAM RAN RAP RAS RAT RAW RAX RAY REB REC RED REE REG REI REM REP RES RET REV REX RHO RIA RIB RID RIF RIG RIM RIN RIP ROB ROC ROD ROE ROM ROT ROW RUB RUE RUG RUM RUN RUT RYA RYE
SAB SAC SAD SAE SAG SAL SAP SAT SAU SAW SAX SAY SEA SEC SEE SEG SEI SEL SEN SER SET SEW SEX SHA SHE SHH SHY SIB SIC SIM SIN SIP SIR SIS SIT SIX SKA SKI SKY SLY SOB SOD SOL SON SOP SOS SOT SOU SOW SOX SOY SPA SPY SRI STY SUB SUE SUM SUN SUP SUQ SYN
TAB TAD TAE TAG TAJ TAM TAN TAO TAP TAR TAS TAT TAU TAV TAW TAX TEA TED TEE TEG TEL TEN TET TEW THE THO THY TIC TIE TIL TIN TIP TIS TIT TOD TOE TOG TOM TON TOO TOP TOR TOT TOW TOY TRY TSK TUB TUG TUI TUN TUP TUT TUX TWA TWO TYE
UDO UGH UKE ULU UMM UMP UNS UPO UPS URB URD URN USE UTA UTE UTS
VAC VAN VAR VAS VAT VAU VAV VAW VEE VEG VET VEX VIA VID VIE VIG VIM VIS VOE VON VOW VOX VUG
WAB WAD WAE WAG WAN WAP WAR WAS WAT WAW WAX WAY WEB WED WEE WEN WET WHA WHO WHY WIG WIN WIS WIT WIZ WOE WOK WON WOO WOP WOS WOT WOW WRY WUD WYE WYN
XIS
YAG YAH YAK YAM YAP YAR YAW YAY YEA YEH YEN YEP YES YET YEW YID YIN YIP YOB YOD YOK YOM YON YOU YOW YUK YUM YUP
ZAG ZAP ZAS ZAX ZED ZEE ZEK ZEN ZIG ZIN ZIP ZIT ZOA ZOO
For additional words (99% of which are valid) check out the Basic Words for Scrabble!