Decode a serialized sketch in your browser

Paste an Apache DataSketches value from MongoDB, Parquet, Delta, Spark or Databricks and read what is inside. It runs on this page: nothing is uploaded.

HLL estimates how many distinct values there are.
Theta estimates distinct values and can be combined with other Theta sketches.
KLL estimates quantiles and percentiles of numbers, such as the median.
Quantiles is the classic quantiles sketch: ranks and percentiles for ordered values.
Frequency finds the most frequent items and their approximate counts.

Try an example The sketch value (base64, hex or Mongo JSON)

Item type

Ranks (KLL, Quantiles)

All items

Theta hashes

JSON

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Not in the browser yet: the compressed Theta layout (the command line tool reads it). Spark and Databricks: SELECT base64(hll_sketch_agg(col)) FROM t, copy the cell and paste it here.