Uppercase & Lowercase Letters
Random letters with the case under your control: UPPERCASE, lowercase, or the mixed 52-letter pool where A and a are separate, equally likely letters — draws like A h Z a. All in your browser.
Generate letters by case
"Both cases" draws from all 52 forms — the result box reports the exact pool used.
A pool of 52, not a coin flip on 26
There are two ways to build "random letters in random case", and they are not equivalent in general. This tool takes the principled one: the pool literally contains all 52 forms, A–Z then a–z, and rejection sampling makes each entry exactly 1/52 likely. The worked example in the intro — A h Z a — was drawn at build time by that same engine from scripted bytes 0, 33, 25, 26, which map to the 1st, 34th, 26th, and 27th pool entries. The practical payoff of the pool approach is no-repeat mode: because A and a are distinct entries, "no repeats" can hand you both, and a full draw of 52 is a genuine shuffle of the whole mixed-case alphabet.
Case work: literacy, typing, and programming
Matching uppercase to lowercase forms is a standard early-literacy exercise, and a random
mixed stream keeps flashcard rounds honest — b, d, p, and q confusions surface quickly when
the case and letter are both unpredictable. Typing practice benefits the same way: shift-key
fluency only develops when capitals arrive unannounced. In programming lessons, a mixed draw
is a quick source of case-sensitivity examples ("is a equal to
A?"). When you need whole strings rather than single letters, the
Random Letter Sequence tool offers the same mixed-case pool
at any length up to 100.
Related generators
The main generator combines case control with vowel/consonant filters and custom pools — mixed-case vowels only, for instance, is a 10-letter pool. The Vowel and Consonant generators keep the single-purpose versions one click away, and the Greek Letter Generator applies the same case machinery to Α/α through Ω/ω.
Frequently asked questions
How does the mixed-case pool work?
The "both cases" option builds a 52-letter pool: A through Z followed by a through z, each an independent entry with probability exactly 1/52 per draw. The engine does not draw a letter and then flip a coin for its case — the pool itself contains both forms, which is what makes uniformity provable and lets no-repeat mode treat A and a as different letters.
In no-repeat mode, can I get both A and a?
Yes. Sampling without replacement removes the exact pool entry that was drawn, and A and a are different entries. A no-repeat draw of all 52 gives you a uniformly random ordering of the complete mixed-case alphabet.
Why would I want mixed-case letters?
Letter-recognition practice is the big one: matching uppercase to lowercase forms is an early-literacy skill, and a random stream of mixed forms makes flash rounds honest. Mixed case also suits case-sensitivity demonstrations in programming lessons and any game where B and b should count as different symbols.
Is a mixed-case draw "more random" than an uppercase one?
Each draw carries more information — log2(52) ≈ 5.7 bits versus log2(26) ≈ 4.7 — because the pool is larger. But both are equally uniform: uniformity is about every pool member being equally likely, not about pool size.
Does anything leave my browser?
No. Draws run locally against your device’s cryptographic random source and are never transmitted, logged, or stored.
Uniform means uniform: in the mixed pool every one of the 52 forms has probability exactly 1/52 — no weighting, ever. Draws are local to your browser and never transmitted. See the methodology page.