Compare
JSON Lines vs Avro
JSON Lines stores one JSON value per UTF-8 line for record-by-record processing. Avro encodes typed records using a writer schema and can store schema metadata with data blocks.
Which format should you choose?
Use JSON Lines for readable events, text tools, and simple line streaming. Consider Avro for typed records and managed schema resolution in data pipelines.
Good fit for JSON Lines
Logs and records processed line by line · Streaming exchange of JSON records
- Reading and writing records incrementally
- Appending or combining text data with common tools
Good fit for Avro
Exchange records with a defined schema
- Events and data pipelines that track schema versions
Basic information
| Field | JSON Lines | Avro |
|---|---|---|
| Extension | .jsonl, .ndjson | .avro |
| MIME type | application/jsonl | application/avro |
| Common uses | Logs and records processed line by line · Streaming exchange of JSON records | Exchange records with a defined schema |
| How to open | Open the file in a text editor or a JSON Lines-aware tool. Validating each line as JSON makes it easier to identify the record containing a syntax error. | Use an Avro-aware tool to inspect the schema, fields, types, and records. |
| Export or convert | To create a JSON array, collect the lines as array elements. To convert an array to JSON Lines, write each value on its own line. For large files, consider memory use during conversion. | When converting to JSON or Parquet, verify field names, types, nulls, logical types, record counts, and schema compatibility. |
Choose by use case
Reading and writing records incrementally
Logs and records processed line by line · Streaming exchange of JSON records
JSON LinesAppending or combining text data with common tools
Logs and records processed line by line · Streaming exchange of JSON records
JSON LinesEvents and data pipelines that track schema versions
Exchange records with a defined schema
AvroKey point 1
A JSON Lines reader can parse each JSON value without a separate schema; an Avro binary reader needs the writer schema.
More on the differencesKey point 2
Appending complete JSON Lines is a text operation; an Avro container writer must maintain valid blocks and synchronization markers.
More on the differencesMore on the differences
Benchmark actual data and readers; neither format is always smaller or faster.
- JSON Lines has independent JSON values per line; Avro records follow a declared schema.
- Avro container files store writer-schema metadata with blocks; JSON Lines is plain UTF-8 text.
- Readers can resolve supported Avro writer/reader schema changes; JSON Lines leaves field and type conventions to applications.
Frequently asked questions
Is JSON Lines the same as Avro JSON encoding?
No. JSON Lines separates ordinary JSON values by lines. Avro JSON encoding still follows Avro's schema and union rules.