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Tool 189 of 244 · Architecture

Bloom Filter Calculator

Sizes Bloom filters and cuckoo filters for a target false-positive rate, with a live insert and query demo.

Bloom Filter Calculator

Size the filter

FilterBits (or buckets)MemoryHashesFalse-positive rate

Live demo

    01

    What it does

    Sizes Bloom filters and cuckoo filters for a target false-positive rate, with a live insert and query demo.

    • Formulas m = -n ln p / (ln 2)^2, k = m/n ln 2; counting and scalable variants; cuckoo filter bits per item; live demo with MurmurHash3/xx…

    02

    Private by design

    Everything happens in your browser. Nothing you type, paste or upload is sent anywhere, and it keeps working offline once the page has loaded.

    03

    What you get

    Recommended size and a live insert/query demo, with a Copy and a Download button on every result.

    • Bloom filter
    • Cuckoo filter
    • Hashing

    Why it matters

    Sizes Bloom filters and cuckoo filters for a target false-positive rate, with a live insert and query demo.

    Formulas m = -n ln p / (ln 2)^2, k = m/n ln 2; counting and scalable variants; cuckoo filter bits per item; live demo with MurmurHash3/xxHash32 double hashing in JS and empirical FP measurement chart vs theory. Everything runs in your browser; nothing you paste is sent unless you press Fetch.

    How to use it

    1. Paste or type the input the tool asks for.
    2. Read the summary and the table or preview.
    3. Adjust the options if you need a different result.
    4. Copy or download the output. Nothing leaves this page.

    FAQ

    Is my input uploaded?

    No. The work runs in your browser and nothing you type, paste or upload is sent anywhere.

    Will this change my site for me?

    No. It shows results and, where it writes rules or files, you copy them and apply them yourself.

    Can I rely on this as official guidance?

    It follows public documentation and well-known algorithms, and tells you where it is a subset or a simulation. Confirm critical changes in the official tool or a staging environment.

    Work with me

    Want a site that gets these right?

    I build fast, accessible websites and web apps that pass these checks from day one. Tell me about your project and I'll reply personally with honest next steps.

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