Convert NDJSON to PGSQL
Upload a .json or .ndjson file and get back a PGSQL SQL script you can load straight into your database. Types are preserved rather than flattened to text. Free, no registration, up to 10MB.
Click to upload or drag and drop
CSV, Excel, SQLite, SQL, DBF (max 10 MB)
How your data is typed in PGSQL
Generated from the converter's own PGSQL type mapping — this is what it actually emits, not an example.
| Your data | PGSQL type |
|---|---|
| Whole number | BIGINT |
| Decimal (money) | NUMERIC(10,2) |
| Floating point | DOUBLE PRECISION |
| True / false | BOOLEAN |
| Date | DATE |
| Date and time | TIMESTAMP |
| Short text | TEXT |
| Long text | TEXT |
| Binary data | BYTEA |
Working from an .ndjson file
Newline-delimited JSON is one complete object per line with no enclosing array, which is exactly what makes it appendable: a log or an export can keep growing without anything having to rewrite the end of the file.
- →Each line is parsed on its own and blank lines are ignored, but a single malformed or truncated line fails the whole file - the usual outcome of copying a log that was still being written.
- →Lines need not share their keys. The columns are what the records collectively use, and a record that omits one gets NULL in that column.
- →A file that is one line long and wraps its array, {"rows": [...]}, is unwrapped into those rows rather than read as a single record.
Loading into an application's database
PGSQL is the name PostgreSQL wears inside application code: PHP's pgsql extension, Laravel's pgsql connection driver, the pdo_pgsql DSN prefix. If that is where you met the name, the database you are loading into probably belongs to a framework, which changes what to watch for.
- →The script creates its own tables. Point it at a schema your migrations own and the next migration run and this file will disagree about who defines the table - load into an empty schema, or a database of its own, and point the application at that.
- →Because every identifier is double-quoted, the case the source used is the case that gets stored. A column that arrives as "CustomerID" has to be quoted in your queries too: an unquoted CustomerID folds to customerid and is not found.
- →No FOREIGN KEY, index or view statement is generated at all, so a framework that introspects the database finds unrelated tables. Declare the relations in your models, or add them with ALTER TABLE once the rows are in.
Reading NDJSON
- →JSON types are trusted: 1 and "1" stay different things.
- →Numbers with a decimal point are read as exact decimals rather than floats.
- →Both an array of objects and newline-delimited JSON work, and a wrapped array like {"data": [...]} is unwrapped automatically.
- →Nested objects are kept as JSON rather than flattened into invented column names.
Writing PGSQL
- →Backslashes are left alone, because PostgreSQL treats them as ordinary characters — doubling them would corrupt every Windows path.
- →Auto-increment columns become GENERATED BY DEFAULT AS IDENTITY.
- →Binary data is written as bytea, and identifiers respect the 63-character limit.
What you get
A ZIP containing dump.sql, plus a README with the exact command to load it. If anything about your data needed a judgement call, a _warnings.txt explains it.
Load this dump into PostgreSQL: psql -U USER -d DATABASE -f dump.sql Create the database first if it does not exist: createdb -U USER DATABASE
Questions
- Is converting NDJSON to PGSQL free?
- Yes. Files up to 10MB convert free with no account. There is a limit of five conversions per day per IP address.
- Will my NDJSON data keep its types in PGSQL?
- Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real PGSQL types rather than everything becoming text. The mapping table above shows exactly what you get.
- Do you store my file?
- No. The file is written to a temporary directory, converted, and the directory is deleted as soon as your download has been sent.