Richard Heaton's Index to Digitalised British and Irish Newspapers Online Beta (updated to 10th September 2015
after Rootsweb backup failure)

Introduction

I have used Newspapers as a source for my research since the 1980's. Back then it was microfilm reading through frame by frame and if fortunate a card index might be available. Now it is increasingly a digital world, yet with so many silo's of information it is difficult to get an overview. So I thought it was time to pull together a comprehensive list of all the material that has been digitalised (so far) as a Guide for other researchers. This is my first attempt and there will be errors and some material will be missed - nonetheless I am confident it should prove helpful for researchers.
Below you will find links to Lists of Newspapers for spanning 31 online archives (listed at the foot of the page). The lists are split as follows : England (excluding London); London (meriting a separate section); Ireland, Scotland; Wales; Channel Islands; and Isle of Man. The lists are sorted by County then by Town and then by Date with the exception of the Main London List which because of its size and complexity is sorted by Title and then Date of Coverage.

But Before You Dive In

Not all the collections have links - The Burney Collection is available free if you are participating in Higher or Further Education in the UK and the 19th Century British Newspapers are free (often at home) through your County Library. You will need to contact your own library service to see whether you can access these records.
The other point to make is that Mass Digitalisation is not always as accurate as we might like to believe. Most of this is out of the control of the businesses creating the digitalised newspapers. For example : the original material (newspaper) may not be in good condition; the images may have been taken from tightly bound volumes so that the text in the "gutter" is lost or difficult to read; and parts of pages may have faded or suffered from foxing.
Do keep an eye out for common issues with digitalisation : VV for W ; II for H; u and n can get mixed up; m can become in and iu; and pre 1808 in the UK you would find the long or serpentine s - it looks quite similar to an f and often is interpreted as an f (the earliest British newspaper I have seen without the long s is dated 1790).
** Finally a self interest warning a very small number of the links covering 3000+ newspapers (about 10% of my personal collection) go to my other very minor website Last Chance to Read. **

Very Best of Luck with Your Research.