The Frequentizer.

This is a Javascript tool for analyzing phoneme frequencies in a language. Enter your text corpus in the large box to the left. In the smaller boxes to the right, list the graphemes that the language uses, including polygraphs that should be treated as single segments, as well as non-letter characters that should be interpreted as letters. You can also use these boxes to match variant spellings to a single sound by listing these variants on the same line, separated by a space. Adjust the additional options as you like and hit Analyze Frequencies to see the result. You can then select different views of the data in a couple of display option listboxes. Use cut and paste to save your text corpus and grapheme definitions.
— Jan Strasser, 2013

This is beta code; please report any errors to me at cedh at conlang org.

Input

Text corpus

Consonants

Vowels

Options

Syllable divider:
You can add this character to the corpus text to specify
explicit syllable breaks in positions where the default rule
V·V, V·CV, VC·C(C)(C)V does not give the intended result.

Treat unknown characters as:
consonants vowels separate category

Ignore UPPER/lower case distinction
Ignore punctuation characters
Ignore numbers

Frequency Analysis

Display options:

Diagram size: * pixels

v0.4 beta, 7 June 2013