v3.26.1
Shareholder Report
 12 Months Ended
Mar. 31, 2026
USD ($)
$ / shares
Shareholder Report [Line Items]  
Document Type N-CSR
Amendment Flag false
Registrant Name Franklin ETF Trust
Entity Central Index Key 0001551895
Entity Investment Company Type N-1A
Document Period End Date Mar. 31, 2026
Shareholder Report Annual or Semi-Annual annual shareholder report
Franklin Short Duration U.S. Government ETF  
Shareholder Report [Line Items]  
Fund Name Franklin Short Duration U.S. Government ETF
Class Name Franklin Short Duration U.S. Government ETF
Trading Symbol FTSD
Security Exchange Name NYSEArca
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Franklin Short Duration U.S. Government ETF for the period April 1, 2025, to March 31, 2026.
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.
Material Fund Change Notice [Text Block]
This report describes changes to the Fund that occurred during the reporting period.
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 YEAR? (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*
Franklin Short Duration U.S. Government ETF
$25
0.24%
[1]
Expenses Paid, Amount $ 25
Expense Ratio, Percent 0.24%
Factors Affecting Performance [Text Block]
HOW DID THE FUND PERFORM LAST YEAR AND WHAT AFFECTED ITS PERFORMANCE?
For the twelve months ended March 31, 2026, Franklin Short Duration U.S. Government ETF returned 4.49%. The Fund compares its performance to the  Bloomberg U.S. Government (1-3 Year) Index, which returned 3.77% for the same period.
PERFORMANCE HIGHLIGHTS
Top contributors to performance:
↑
Exposure to agency mortgage-backed securities was the main contributor to relative performance.
↑
Allocation relative to the benchmark in Delegated Underwriting and Servicing (DUS) and collateralized mortgage obligation securities contributed to results.
There were no significant detractors from performance during the period.
Use of derivatives and the impact on performance:
The Fund utilized interest rate futures to manage its duration exposure, which detracted from performance.
Performance Past Does Not Indicate Future [Text] The Fund’s past performance is not necessarily an indication of how the Fund will perform in the future.
Line Graph [Table Text Block]
image
Average Annual Return [Table Text Block]
AVERAGE ANNUAL TOTAL RETURNS (%) Period Ended March 31, 2026
 
1 Year
5 Year
10 Year
Franklin Short Duration U.S. Government ETF (NAV)
4.49
2.38
2.03
Bloomberg U.S. Aggregate Index
4.35
0.31
1.70
Bloomberg U.S. Government (1-3 Year) Index
3.77
1.83
1.78
No Deduction of Taxes [Text Block] The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.
Material Change Date Apr. 01, 2025
Updated Performance Information Location [Text Block]
For current month-end performance, please call Franklin Templeton at (800) DIAL BEN/342-5236 or visit
https://www.franklintempleton.com/investments/options/exchange-traded-funds.
Important data provider notices and terms available at www.franklintempletondatasources.com.
Net Assets $ 281,320,019
Holdings Count | $ / shares 336
Advisory Fees Paid, Amount $ 588,157
Investment Company Portfolio Turnover 61.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of March 31, 2026)
Total Net Assets
$281,320,019
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)
336
Total Management Fee Paid (based on a unitary fee)
$588,157
Portfolio Turnover Rate
61%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of March 31, 2026)
Portfolio Composition* (% of Total Investments)
image
 [2]
Material Fund Change [Text Block]
HOW HAS THE FUND CHANGED?
Effective December 31, 2025, Paul Varunok stepped down as portfolio manager of the Fund.
This is a summary of a certain change to the Fund since  April 1, 2025. For more complete information, you may review the Fund’s current prospectus and the Fund’s next prospectus, which we expect to be available by August 1, 2026, at https://www.franklintempleton.com/regulatory-fund-documents or upon request at (800) DIAL BEN/342-5236 or ETFs-Product@franklintempleton.com.
Summary of Change Legend [Text Block] This is a summary of a certain change to the Fund since  April 1, 2025. For more complete information, you may review the Fund’s current prospectus and the Fund’s next prospectus, which we expect to be available by August 1, 2026, at https://www.franklintempleton.com/regulatory-fund-documents or upon request at (800) DIAL BEN/342-5236 or ETFs-Product@franklintempleton.com.
Updated Prospectus Phone Number (800) DIAL BEN/342-5236
Updated Prospectus Email Address ETFs-Product@franklintempleton.com
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.
[2]
* Does not include derivatives, except purchased options, if any.