5 MB Avro sample file

An Avro file of exactly 5,242,880 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 5 MB sample, test or dummy Avro file.

sample-avro-5mb.avro

5 MB5,242,880 bytes

Download 5 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: 61df0bc624bf5a172814c9140ffe11ae66d5fb901152c6a8bc127d439aa5623e
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 42,340 binary-encoded customer records in 428 blocks. 120 bytes of filler in an extra header metadata entry, which readers ignore, bring the file to the exact size.

Records	42,340
Blocks	428, 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-5mb.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 5 MB matters

A 5,242,880-byte file: the size of a phone photo and the minimum part size for S3 multipart uploads. These are the default limits a file of this size is useful for testing:

System	Limit	Note
PHP	2 MB per uploaded file by default (upload_max_filesize)	A 5 MB upload fails on an untuned PHP installation.
Vercel Functions	4.5 MB request body	Larger uploads must go directly to object storage.
Amazon S3 multipart upload	5 MiB minimum part size	This file is exactly one minimum part.
AWS Lambda	6 MB synchronous invocation payload	5 MB of binary data exceeds it once base64-encoded.
Browser localStorage	About 5 MB per origin	Storing this file as text fills the quota.
Django	2.5 MB in memory by default	Larger uploads are streamed to a temporary file instead of held in memory.

All 5 MB sample files

Use this file for

Testing image resizing and memory use
Verifying handling of logical types such as dates and UUIDs
Load-testing readers with many blocks

Testing notes for Avro

An Avro message taken from Kafka is not a container file. It has no header and no embedded schema, only a schema ID, so tools made for .avro files cannot open it.
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.

Avro format reference

Technical details

File name	sample-avro-5mb.avro
Format	Avro (Apache Avro object container file)
Extension	.avro
MIME type	application/avro
Size	5,242,880 bytes (5 MB)
Kind	Binary
Signature	4F 62 6A 01
SHA-256	61df0bc624bf5a172814c9140ffe11ae66d5fb901152c6a8bc127d439aa5623e
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-5mb.avro     # Linux
shasum -a 256 sample-avro-5mb.avro # macOS

On Windows, run Get-FileHash sample-avro-5mb.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 5 MB?: Yes. It is 5,242,880 bytes, which is 5 MB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
What is inside the 5 MB Avro file?: An object container file whose header carries the writer schema as JSON, followed by 42,619 binary-encoded customer records in 427 blocks. 1 bytes of filler in an extra header metadata entry, which readers ignore, bring the file to the exact size.
What schema do the Avro samples use?: A Customer record of twelve fields: a long, strings, a double, a boolean, an enum, a union with null, and two logical types, uuid and date. The schema is in the header of every file as JSON.

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