v3.26.1
Shareholder Report
 6 Months Ended
Jan. 31, 2026
USD ($)
$ / shares
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name Putnam Tax Free Income Trust
Entity Central Index Key 0000771951
Entity Investment Company Type N-1A
Document Period End Date Jan. 31, 2026
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Class A  
Shareholder Report [Line Items]  
Fund Name Putnam Strategic Intermediate Municipal Fund
Class Name Class A
Trading Symbol PPNAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Putnam Strategic Intermediate Municipal Fund for the period August 1, 2025, to January 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) 225-1581.
Additional Information Phone Number (800) 225-1581
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)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class A
$46
0.88%
[1],[2]
Expenses Paid, Amount $ 46
Expense Ratio, Percent 0.88%
Net Assets $ 2,296,413,779
Holdings Count | $ / shares 829
Investment Company Portfolio Turnover 23.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of January 31, 2026)
Total Net Assets
$2,296,413,779
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)
829
Portfolio Turnover Rate
23%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of January 31, 2026)
Portfolio Composition*  (% of Total Investments)
image
 [3]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class C  
Shareholder Report [Line Items]  
Fund Name Putnam Strategic Intermediate Municipal Fund
Class Name Class C
Trading Symbol PAMTX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Putnam Strategic Intermediate Municipal Fund for the period August 1, 2025, to January 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) 225-1581.
Additional Information Phone Number (800) 225-1581
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)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class C
$84
1.62%
[4],[5]
Expenses Paid, Amount $ 84
Expense Ratio, Percent 1.62%
Net Assets $ 2,296,413,779
Holdings Count | $ / shares 829
Investment Company Portfolio Turnover 23.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of January 31, 2026)
Total Net Assets
$2,296,413,779
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)
829
Portfolio Turnover Rate
23%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of January 31, 2026)
Portfolio Composition*  (% of Total Investments)
image
 [6]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class R6  
Shareholder Report [Line Items]  
Fund Name Putnam Strategic Intermediate Municipal Fund
Class Name Class R6
Trading Symbol PAMLX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Putnam Strategic Intermediate Municipal Fund for the period August 1, 2025, to January 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) 225-1581.
Additional Information Phone Number (800) 225-1581
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)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class R6
$28
0.55%
[7],[8]
Expenses Paid, Amount $ 28
Expense Ratio, Percent 0.55%
Net Assets $ 2,296,413,779
Holdings Count | $ / shares 829
Investment Company Portfolio Turnover 23.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of January 31, 2026)
Total Net Assets
$2,296,413,779
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)
829
Portfolio Turnover Rate
23%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of January 31, 2026)
Portfolio Composition*  (% of Total Investments)
image
 [9]
Updated Prospectus Web Address https://www.franklintempleton.com/regulatory-fund-documents
Class Y  
Shareholder Report [Line Items]  
Fund Name Putnam Strategic Intermediate Municipal Fund
Class Name Class Y
Trading Symbol PAMYX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Putnam Strategic Intermediate Municipal Fund for the period August 1, 2025, to January 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) 225-1581.
Additional Information Phone Number (800) 225-1581
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)
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment*,†
Class Y
$32
0.62%
[10],[11]
Expenses Paid, Amount $ 32
Expense Ratio, Percent 0.62%
Net Assets $ 2,296,413,779
Holdings Count | $ / shares 829
Investment Company Portfolio Turnover 23.00%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (as of January 31, 2026)
Total Net Assets
$2,296,413,779
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)
829
Portfolio Turnover Rate
23%
Holdings [Text Block]
WHAT DID THE FUND INVEST IN? (as of January 31, 2026)
Portfolio Composition*  (% of Total Investments)
image
 [12]
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]
† Annualized.
[3]
* Does not include derivatives, except purchased options, if any.  
[4]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[5]
† Annualized.
[6]
* Does not include derivatives, except purchased options, if any.  
[7]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[8]
† Annualized.
[9]
* Does not include derivatives, except purchased options, if any.  
[10]
* Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.
[11]
† Annualized.
[12]
* Does not include derivatives, except purchased options, if any.