British army browse records at Findmypast

More than 7.8 million British Army Service records from the following series are now available to browse. These Army documents including attestation papers, medical forms, discharge documents and pension claims.

WO 22 - Royal Hospital Chelsea: Returns Of Payment Of Army and Other Pensions 1842-1883
WO 23 - Royal Hospital Chelsea: Admission Books, Registers, and Papers 1702-1876
WO 76 - Regimental Records Of Officers' Services 1775-1914
WO 96 - Militia Service Records 1806-1915
WO 97 - Chelsea Pensioners British Army Service Records 1760-1913
WO 121 - Chelsea: Pensioners' Discharge Documents 1760-1887
WO 122 - Chelsea: Pensioners' Discharge Documents, Foreign Regiments 1816-1817
WO 128 - Imperial Yeomanry, Soldiers' Documents, South African War 1899-1902
WO 131 - Chelsea: Documents Of Soldiers Awarded Deferred Pensions 1838-1896
WO 400 - The Household Cavalry 1801-1919

WO 96 with 2,196,559 images and WO 97 with 6,121,455 images account for the bulk of these records. for which there's a link above to the TNA description above.  Note that although TNA include a note that WO 97 does not include war dead the one record I examined had papers for a serviceman whu died in action in October 1917.