What is the size limit of a cosmosdb item?

Question

I\'ve been looking for a authoritative source of azure cosmosdb limits by I can\'t find one. In particular, I need to know the size limits for a individual item.

Answer 1

The maximum size of a document today is 2MB.

https://docs.microsoft.com/en-us/azure/cosmos-db/documentdb-resources#documents

Answer 2

So this is one of those things that always annoys me about documentation.
Sure it's 2MB, but by who's measuring stick.

TLDR: Between 2,090,014 and 2,100,014 when Encoding.UTF8.GetByteCount(doc) or Encoding.ASCII.GetByteCount(doc)

To get there I set up the following code:

 for (int i = 10; i < 10000; i++)
        {
            var docItem = new TestItem(new string('A', i * 10000));
            string doc = JsonConvert.SerializeObject(docItem);
            log.LogInformation(" ");
            log.LogInformation(" -------------------------------------------------------------------------------------------------------------------------------------");
            log.LogInformation($" -------------------------------------------------        Doc Size = {i*10000 }       --------------------------------------------------");
            log.LogInformation(" -------------------------------------------------------------------------------------------------------------------------------------");
            
            log.LogWarning($"UTF7 - {Encoding.UTF7.GetByteCount(doc)}");
            log.LogWarning($"UTF8 - {Encoding.UTF8.GetByteCount(doc)}");
            log.LogWarning($"UTF32 - {Encoding.UTF32.GetByteCount(doc)}");
            log.LogWarning($"Unicode - {Encoding.Unicode.GetByteCount(doc)}");
            log.LogWarning($"Ascii - {Encoding.ASCII.GetByteCount(doc)}");
            log.LogInformation(" -------------------------------------------------------------------------------------------------------------------------------------");
            log.LogWarning($"UTF7 - {ASCIIEncoding.UTF7.GetByteCount(doc)}");
            log.LogWarning($"UTF8 - {ASCIIEncoding.UTF8.GetByteCount(doc)}");
            log.LogWarning($"UTF32 - {ASCIIEncoding.UTF32.GetByteCount(doc)}");
            log.LogWarning($"Unicode - {ASCIIEncoding.Unicode.GetByteCount(doc)}");
            log.LogWarning($"Ascii - {ASCIIEncoding.ASCII.GetByteCount(doc)}");
            try
            {
                await cosmosStore.CreateDocumentAsync(docItem);
            }
            catch (Exception e)
            {
                log.LogWarning(e.Message + "Caught");
            }
        }

And here's where it broke: