| Form N-CSR Cover | 6 Months Ended |
| Oct. 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | Putnam ETF Trust |
| Entity Central Index Key | 0001845809 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Oct. 31, 2024 |
| Shareholder Report | 6 Months Ended | |
| Oct. 31, 2024 USD ($) $ / shares | ||
| Shareholder Report [Line Items] | ||
| Document Type | N-CSRS | |
| Amendment Flag | false | |
| Registrant Name | Putnam ETF Trust | |
| Entity Central Index Key | 0001845809 | |
| Entity Investment Company Type | N-1A | |
| Document Period End Date | Oct. 31, 2024 | |
| Putnam ESG High Yield ETF | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Putnam ESG High Yield ETF | |
| Class Name | Putnam ESG High Yield ETF | |
| Trading Symbol | PHYD | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about Putnam ESG High Yield ETF for the period May 1, 2024, to October 31, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents . You can also request this information by contacting us at (800) DIAL BEN/342-5236 . | |
| Additional Information Phone Number | (800) DIAL BEN/342-5236 | |
| Additional Information Website | https://www.franklintempleton.com/regulatory-fund-documents | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment) Fund Name Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment * , † Putnam ESG High Yield ETF $28 0.53% | [1],[2] |
| Expenses Paid, Amount | $ 28 | |
| Expense Ratio, Percent | 0.53% | |
| Net Assets | $ 163,502,470 | |
| Holdings Count | $ / shares | 318 | [3] |
| Investment Company Portfolio Turnover | 23% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (as of October 31, 2024) Total Net Assets $163,502,470 Total Number of Portfolio Holdings * 318 Portfolio Turnover Rate 23% | [3] |
| Holdings [Text Block] | [4] | |
| Updated Prospectus Web Address | https://www.franklintempleton.com/regulatory-fund-documents | |
| [1] * Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher. † Annualized. * Includes derivatives, if applicable. Cash and Equivalents, if any, represent the market value weights of cash, derivatives, short-term securities, and other unclassified assets in the portfolio. Allocations may not total 100% because the chart includes the notional value of certain derivatives (the economic value for purposes of calculating periodic payment obligations), in addition to the market value of securities. Holdings and allocations may vary over time. | ||
| Label | Element | Value |
| Putnam ESG High Yield ETF | Consumer Cyclicals [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 24.40% |
| Putnam ESG High Yield ETF | Capital Goods [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 10.60% |
| Putnam ESG High Yield ETF | Basic Materials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 10.40% |
| Putnam ESG High Yield ETF | Financials [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 9.70% |
| Putnam ESG High Yield ETF | Health Care [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 8.60% |
| Putnam ESG High Yield ETF | Technology [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 7.20% |
| Putnam ESG High Yield ETF | Energy [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 7.10% |
| Putnam ESG High Yield ETF | Consumer Staples [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 6.90% |
| Putnam ESG High Yield ETF | Communication Services [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 5.50% |
| Putnam ESG High Yield ETF | Non-Cash Investments [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 3.80% |
| Putnam ESG High Yield ETF | Utilities [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 2.30% |
| Putnam ESG High Yield ETF | Transportation [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 0.90% |
| Putnam ESG High Yield ETF | Cash and Equivalents [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 6.50% |
