Best practice for comma separated input size for the search field

Question

I am working with large number of entries in web UI such as IoT device list with IMEI. There is a need to make quick multiple selection by IMEI.

Would it be good practice to provide search field with possibility to enter comma separated IMEIs? In most cases those IMEIs will be pasted into search field.

What would be sane maximum limit for such input? 50 IMEIs (850 symbols), 100 IMEIs (1700 symbols), even more? What is main bottle neck for such solution?

I understand CSV file import could be used, but we want a quicker solution.

UPDATE.

Answering the question:

could you explain IMEI and provide a screenshot/ wireframe of what you have tried already?

In search field we are planning to add option "Paste multiple" as in wireframe below

Then user will be prompted additional window to paste multiple IMEIs

Is it correct approach?

Actually we consider adding csv file import option later.

Answer 1

So to reiterate:

• Users have .csvs or other files where large numbers of IMEis are listed
• They need to be able to search for these IMEIs in your system

Ideally you'd have access to analytics or user interviews that could help you define the upper limit users search. It sounds like you don't have access to either, so in the meantime we can make a few assumptions.

As you said, it seems the most likely scenario is that they'll be copying and pasting these numbers, as they are difficult to correctly input due to their length. They likely won't be checking their work, again due to length, so displaying the pasted content is mostly irrelevant - you can display "1234567890abcde, 1234567890abcde, and 498 more", which should give them enough information about their search to complete their task.

The main bottleneck will likely be your backend system, not the UI. If you paste 500 IMEIs, how fast does the system respond? If it slows at any point and effects the UX, you've found your limit. If it responds adequately for 10,000 IMEIs, there's little reason to limit it at all.