Document generation for letters
When the job is letters, 30 tools in this guide list it as a use case. The most common data sources are JSON API (16), built-in forms (12) and Google Sheets (8). Our order puts Gavel, Fluent (Windward) and Xpertdoc at the top.
- Tools
- 30
- With USD price
- 15, from $5
- Free tier
- 16
- Editor's picks
- 1
- Checked
- 20 Oct 2026
- 01
Formerly Documate (Documate Inc. dba Gavel).
Outputs DOCX, PDF Template Word, PDF form Reads built-in forms, API, Zapier/Make/n8n$83 / mo - 02
Fluent (Windward) windwardstudios.comFormerly Windward Studios, acquired by PDFTron (now Apryse).
Outputs PDF, DOCX, XLSX, PPTX, HTML Template Word Reads API, Salesforce, Excel G2 4.4 (77)On request - 03 Xpertdoc xpertdoc.com
CCM and document generation with Microsoft Dynamics CRM connector.
Outputs PDF, DOCX, email, e-sign documents Template Word Reads API G2 4.3 (26)On request - 04
Micro $19.50/mo shown; price formatting unclear on page.
Outputs DOCX, XLSX, PDF Template Word Reads Google Sheets, CSV, Excel, API +2$19.50 / mo - 05
Document Studio digitalinspiration.comBy Digital Inspiration. Standard $79/yr (computed $6.58/mo).
Outputs PDF, Google Docs, Google Slides, email, e-sign documents Template Google Docs Reads Google Sheets, Google Forms, Excel$6.58 / mo - 06
MailMergic mailmergic.comPDF mail merge from Sheets.
Outputs PDF, DOCX, XLSX, email Template PDF form Reads Google Sheets, Excel, CSV, Zapier/Make/n8n$39 / mo - 07
Individual $33/mo billed $390/yr.
Outputs PDF, DOCX, e-sign documents Template Word, Visual builder Reads built-in forms, API, Zapier/Make/n8n$33 / mo - 08
Knackly knackly.ioLegal document automation.
Outputs DOCX, PDF Template Word Reads built-in forms, API, Zapier/Make/n8n$209 / mo - 09
Sheetgo sheetgo.comSpreadsheet automation. Document generation and mail merge on Pro ($35/mo annual, $50 monthly).
Outputs PDF, Google Docs, email Template Google Docs Reads Google Sheets, Excel$35 / mo - 10
Templafy templafy.comAI document agents in Microsoft Office.
Outputs PPTX, DOCX, PDF Template Word Reads Salesforce, API$40 / mo - 11
Apsona apsona.comDoc and email merge in all bundles.
Outputs PDF, DOCX, email Template Word Reads Salesforce$125 / mo - 12
Docmosis docmosis.comCloud Professional $49/mo, 4,000+ pages.
Outputs PDF, DOCX, HTML Template Word Reads API$49 / mo
12 of 30 shown Show the other 18Hide the other 18
- 13
Docs Creator copa-webservices.deMail merge add-on for Sheets.
Outputs Google Docs, PDF, email Template Google Docs Reads Google Sheets$5 EUR 50/yr, converted - 14
Docxpresso docxpresso.comEUR pricing shown as Core 2500 EUR/user/mo (likely 25.00, formatting unclear).
Outputs PDF, DOCX Template Word Reads built-in forms, API$27 EUR 25/user, converted - 15 docxtemplater docxtemplater.com
JS library, MIT/GPLv3 core.
Outputs DOCX, PPTX, XLSX Template Word Reads API$45 EUR 500/yr, converted - 16
MyCase Document Automation mycase.comLegal PM with Word-based automation (Woodpecker redirects here).
Outputs DOCX, PDF, e-sign documents Template Word Reads built-in forms$79 / mo - 17
Inkit inkit.comSecure document generation and e-sign.
Outputs PDF, e-sign documents Template HTML Reads API$15 / mo - 18
Zoho Writer zoho.comFree editor with Document Automation add-on credits (200/mo free).
Outputs PDF, DOCX, e-sign documents, email Template Word Reads Zoho, built-in forms, CSVNot published free tier - 19
Aspose.Words products.aspose.comSDK. Developer Small Business license $1,679 perpetual.
Outputs PDF, DOCX, HTML, Markdown Template Word Reads APIOn request - 20
Autocrat workspace.google.comFree Sheets add-on by New Visions CloudLab.
Outputs PDF, Google Docs, email Template Google Docs Reads Google Sheets, Google FormsFree - 21
Docu Merge (Form Notify) formnotify.comFree Sheets add-on, 9,000+ installs.
Outputs PDF, Google Docs, DOCX, email Template Google Docs Reads Google SheetsFree - 22
docassemble docassemble.orgMIT guided-interview and document assembly.
Outputs PDF, DOCX Template Word, PDF form Reads built-in forms, APIFree - 23
HotDocs mitratech.comOwned by Mitratech. Desktop and cloud.
Outputs DOCX, PDF Template Word Reads built-in forms, APIOn request - 24
Nutrient Documents for Salesforce nutrient.ioFree watermarked version installs in org.
Outputs PDF, DOCX, e-sign documents Template Word, Visual builder Reads SalesforceOn request free tier - 25
Adobe Document Generation API developer.adobe.comPart of Adobe PDF Services.
Outputs PDF, DOCX Template Word Reads APIOn request free tier - 26
Avvoka avvoka.comLegal drafting and document automation for law firms.
Outputs DOCX, e-sign documents Template Word Reads built-in formsOn request - 27
Clio Draft clio.comFormerly Lawyaw. Word templates and court forms.
Outputs DOCX, PDF Template Word, PDF form Reads built-in formsNot published - 28 Mergery ljd-tech.com
Free Sheets add-on by LJD Technology.
Outputs PDF, email Template Google Docs Reads Google SheetsFree - 29
Smokeball smokeball.comLegal practice management with document automation and form library.
Outputs DOCX, PDF Template Word Reads built-in formsNot published - 30
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What differs for letters
These tools for letters most often write PDF (28), DOCX (24) and email (10). Templates are built in Word (22), Google Docs (6) and a fillable PDF form (4).
Paid plans start at $5 a month after conversion to dollars with Docs Creator. You can try 16 of them on a free tier. Prices were checked on 20 Oct 2026.
Nearby pages
Related lists: Document generation for contracts (74 tools), Document generation for reports (59), Document generation for invoices (53), Document generation for proposals (34), Document generation for certificates (28), Document generation for quotes (26), Document generation for NDAs (14), Document generation for onboarding packs (12).
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