# Convert binary and encoded text

Shape / columns

base64, hex, blob and character-set conversion

Page: <https://meridian.online/operations/convert-binary-and-encoded-text>

## Status

Runs as a SQL step.

arcform carries it as a `sql:` step today.

## The DuckDB step

base64 and hex, there and back

It reads the `orders` table the proofs share. Create it first:

```sql
CREATE TABLE orders AS SELECT * FROM (VALUES
  (1,  'Alice Ng',      'north', DATE '2026-01-03', 120.00, 'widget', 'a|b',   '{"channel":"web","items":[1,2]}'),
  (2,  'alice ng',      'north', DATE '2026-01-05',  80.50, 'gadget', 'b',     '{"channel":"shop","items":[3]}'),
  (3,  'Bob  Okafor',   'south', DATE '2026-01-05', 300.00, 'widget', 'a|c',   '{"channel":"web","items":[4,5,6]}'),
  (4,  'Carla Díaz',    'east',  DATE '2026-01-09',  NULL,  'gizmo',  NULL,    '{"channel":"web","items":[]}'),
  (5,  'Bob Okafor',    'south', DATE '2026-01-12',  45.25, 'gadget', 'c',     '{"channel":"phone","items":[7]}'),
  (6,  'Dev Patel',     'west',  DATE '2026-01-12', 510.00, 'widget', 'a',     '{"channel":"web","items":[8,9]}'),
  (7,  'Carla Diaz',    'east',  DATE '2026-01-20',  99.99, 'gizmo',  'b|c',   '{"channel":"shop","items":[10]}'),
  (8,  'Dev Patel',     'west',  DATE '2026-02-02', 510.00, 'widget', 'a',     '{"channel":"web","items":[8,9]}'),
  (9,  'Eve Larsen',    NULL,    DATE '2026-02-03',  15.00, 'gadget', NULL,    '{"channel":"web","items":[11]}'),
  (10, 'Alice Ng',      'north', DATE '2026-02-10', 220.00, 'gizmo',  'a|b|c', '{"channel":"phone","items":[12,13]}')
) t(order_id, customer, region, order_date, amount, product, tags, meta);
```

Then run the statement:

```sql
SELECT customer, to_base64(encode(customer)) AS b64, decode(from_base64(to_base64(encode(customer)))) AS back, hex(customer) AS hx FROM orders LIMIT 3;
SELECT CASE WHEN count(*) FILTER (WHERE decode(from_base64(to_base64(encode(customer)))) <> customer) = 0 THEN 'round trip holds'
            ELSE error('base64 round trip changed a value') END AS verdict FROM orders;
```

It needs nothing installed beyond DuckDB itself.

## Variants

- Work with bit strings: Create, combine and inspect strings of bits.
- Convert the character set: Re-encode text from one character set to another.
- Encode or decode base64 and hex: Convert values to and from base64, base32, hex or a binary blob.
- Escape text for a format: Escape or unescape special characters for JSON, XML, CSV or HTML.

## What other tools call it

Meridian's classification; an independent blind rating agreed on 86.2% of 312 rows (exact class, version 2).

- Alteryx Designer: [`Base64 Encoder`](https://help.alteryx.com/current/en/designer/tools/developer/base64-encoder-tool.html) (read 2026-09-27)
- Alteryx Designer: [`Blob Convert`](https://help.alteryx.com/current/en/designer/tools/developer/blob-convert-tool.html) (read 2026-09-27)
- Apache DataFusion: [`Binary String Functions`](https://datafusion.apache.org/user-guide/sql/scalar_functions.html) (read 2026-09-27)
- DuckDB: [`Bitstring Functions (family)`](https://duckdb.org/docs/current/sql/functions/bitstring) (read 2026-09-27)
- DuckDB: [`Blob Functions (family)`](https://duckdb.org/docs/current/sql/functions/blob) (read 2026-09-27)
- Duckle: [`Base64`](https://github.com/slothflowlabs/duckle/blob/f85f8960edfb6efbf4cb89d58a7b32e16df0e867/website/docs/components.html) (read 2026-09-25)
- Apache NiFi: [`ConvertCharacterSet`](https://nifi.apache.org/components/org.apache.nifi.processors.standard.ConvertCharacterSet/) (read 2026-09-27)
- Apache NiFi: [`Encode/Decode Functions`](https://nifi.apache.org/nifi-docs/expression-language-guide.html) (read 2026-09-27)
- Apache NiFi: [`EncodeContent`](https://nifi.apache.org/components/org.apache.nifi.processors.standard.EncodeContent/) (read 2026-09-27)
- Polars: [`Expr.bin (group)`](https://docs.pola.rs/api/python/stable/reference/expressions/binary.html) (read 2026-09-27)
- Polars: [`Expr.str: encode and decode (group)`](https://docs.pola.rs/api/python/stable/reference/expressions/string.html) (read 2026-09-27)