10 MB Avro sample file

An Avro file of exactly 10,485,760 bytes. It is a valid Apache Avro object container file file, generated for this site and checked with an independent parser. Use it wherever you need a 10 MB sample, test or dummy Avro file.

sample-avro-10mb.avro

10 MB10,485,760 bytes

Download 10 MB Avro

Created in your browser in a few seconds, then checked against the SHA-256 checksum. No sign-up.

Type: application/avro
SHA-256: b7bb9375947e639f5ff6b22cf7c81fa95bf7f32e9bc5da10aa27661042e0f9c6
Delivery: Created in your browser. Files of 2 MB and more have no direct URL (why).

What is in this file

An object container file whose header carries the writer schema as JSON, followed by 84,535 binary-encoded customer records in 850 blocks. 125 bytes of filler in an extra header metadata entry, which readers ignore, bring the file to the exact size.

Records	84,535
Blocks	850, of up to 100 records
Schema	Customer record, 12 fields
Types used	long, string, double, boolean, enum, union, and the uuid and date logical types
Codec	null (not compressed)
Sync marker	16 bytes after every block

First bytes of the file

The first 64 bytes of sample-avro-10mb.avro as a hex dump: offset, bytes, then the same bytes as text. The Avro signature is 4F 62 6A 01.

00000000  4f 62 6a 01 06 16 61 76 72 6f 2e 73 63 68 65 6d  |Obj...avro.schem|
00000010  61 d0 0a 7b 22 74 79 70 65 22 3a 22 72 65 63 6f  |a..{"type":"reco|
00000020  72 64 22 2c 22 6e 61 6d 65 22 3a 22 43 75 73 74  |rd","name":"Cust|
00000030  6f 6d 65 72 22 2c 22 6e 61 6d 65 73 70 61 63 65  |omer","namespace|

Preview

Avro files cannot be shown in a browser. Download the file and open it in an application that reads Avro, such as Apache Spark, Flink and Hive.

Where 10 MB matters

A 10,485,760-byte file: over the default limits of PHP, API Gateway and Spring Boot requests. These are the default limits a file of this size is useful for testing:

System	Limit	Note
Amazon API Gateway	10 MB payload	A 10 MB file in a multipart or base64 body is over the limit.
Spring Boot multipart	10 MB per request by default (max-request-size)	Exceeded once form overhead is added.
PHP	8 MB POST body by default (post_max_size)	Rejected before the script runs.
Amazon S3 multipart upload	5 MiB minimum part size	This file splits into exactly two minimum-sized parts.
Email attachments	Commonly 20 to 25 MB per message	10 MB fits, at about 13.3 MB once encoded.

All 10 MB sample files

Use this file for

Measuring download speed from your own server or CDN
Load-testing readers with many blocks
Testing ingestion jobs and bulk loaders

Testing notes for Avro

No media type is registered for Avro, so files arrive labelled application/octet-stream as often as anything else. Detection has to rely on the four signature bytes.
A logical type is an annotation on a plain type: a date is stored as an int counting days since 1970. A reader that ignores the annotation returns a number where a date was expected.

Avro format reference

Technical details

File name	sample-avro-10mb.avro
Format	Avro (Apache Avro object container file)
Extension	.avro
MIME type	application/avro
Size	10,485,760 bytes (10 MB)
Kind	Binary
Signature	4F 62 6A 01
SHA-256	b7bb9375947e639f5ff6b22cf7c81fa95bf7f32e9bc5da10aa27661042e0f9c6
Created	2026-10-14
Validation	Exact size, signature bytes and structure checked when the generator was built; your copy is checked against the SHA-256 after it is created
Preview	Not available for this file; details only
Source	Generated in your browser by this site's generator; not copied from elsewhere
Licence	Free to use, modify and redistribute (terms)
Category	Data

Validated for expected format and integrity. As with any download, scan the file with your own security tools before opening it. How files are made and checked

Verify your copy

This file is created in your browser, so it has no direct URL for curl or wget. The bytes are the same every time and in every browser, so after saving it you can compare its checksum with the SHA-256 value above.

sha256sum sample-avro-10mb.avro     # Linux
shasum -a 256 sample-avro-10mb.avro # macOS

On Windows, run Get-FileHash sample-avro-10mb.avro -Algorithm SHA256 in PowerShell. For scripts and pipelines, save the file once and keep your own copy, or use a 1 MB file, which has a direct URL.

Related files

Questions about this file

Is this file exactly 10 MB?: Yes. It is 10,485,760 bytes, which is 10 MB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
What is inside the 10 MB Avro file?: An object container file whose header carries the writer schema as JSON, followed by 85,116 binary-encoded customer records in 852 blocks. 93 bytes of filler in an extra header metadata entry, which readers ignore, bring the file to the exact size.
Are the Avro samples compressed?: No. They use the "null" codec, which every Avro library is required to support, so the records can also be inspected in a hex viewer.

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