Efficient way to store values in Cypress: Aliases vs cy.task

You may saw that in web automation frameworks we are using either Cypress aliases or cy.task for storing values.
What is the difference between cy.task("saveItem", value) and Cypress aliases cy.wrap().as()?
It is a good question and it has pretty good baseline.
The efficiency of saving an item in Cypress depends on the context of how you plan to use the saved values.
Let’s compare the two approaches:

Using cy.task("saveItem", value)

Best for: Persistent storage or cross-test sharing

This method is used when you need to store data outside of Cypress's test execution environment, such as in a database, a file, or memory storage managed by the Node.js backend.

It enables cross-test persistence, meaning the saved value can be accessed across different test runs.

Example:

Cypress.Commands.add("saveItem", (value) => {
  cy.task("saveItem", value);
});

it("Saves and retrieves data", () => {
  cy.saveItem("myValue");
});

Using aliases cy.wrap(value).as("aliasName")

Best for: Short-term, in-test storage

Aliases are used within the same test or in before/beforeEach hooks but cannot be shared across test cases.

Data stored in an alias is accessible via this.aliasName in function callbacks or with cy.get("@aliasName").

Example:

it("Saves item using alias", function () {
  cy.wrap("myValue").as("savedItem");
  cy.get("@savedItem").then((item) => {
    expect(item).to.equal("myValue");
  });
});

Which is more efficient?

If you need to store values across multiple tests or persist them beyond Cypress's in-memory execution, cy.task() is more efficient.
If you only need to temporarily store data within a single test execution, aliases are more efficient because they are simpler and do not require interaction with the Node.js process.

Recommendation

Use aliases cy.wrap().as() for temporary, within-test storage.
Use cy.task("saveItem", value) when data persistence beyond a single test execution is required.

Let me know your approach to store values in Cypress! 🚀