Templates + JSON, finished documents out
Merge a reusable template with JSON data and get a finished PDF or Word document back, all from a single API call. Pick the tool that fits how your team builds.
They share one API and one mental model. The right fit comes down to where you build the template and what you need back.
Teams comfortable in HTML/CSS who want pixel-perfect, fully custom layouts.
Business users who design in Word and need an editable Word file as the result.
Contracts, invoices and quotes where the design lives in Word but you ship a final PDF.
Still deciding? See them side by side
Every one of our document tools follows the same three-step shape, so the concept transfers no matter which one you choose.
Design the layout once in HTML/CSS or in Microsoft Word. Mark where data should land with placeholders or document fields.
Make one HTTPS request with your template and a JSON object of values: text, numbers, images, tables and conditions.
ConvertAPI merges the two and returns a polished PDF, Word file or image. No template engine to host or maintain.
The same data, three delivery shapes. Here is exactly how they differ.
| Capability | HTML HTML + JSON to PDF | WORD Word Template to DOCX | WORD Word Template to PDF |
|---|---|---|---|
| Where you build the template | HTML & CSS (or Word to HTML) | Microsoft Word | Microsoft Word |
| Who usually owns it | Developers / web team | Business users | Business users |
| Data sent as | JSON (Handlebars {{ }}) | JSON (fields or {{placeholders}}) | JSON (fields or {{placeholders}}) |
| Output format | PDF · PNG · JPG | Editable DOCX | |
| Result is editable | No | Yes | No |
| Pixel-level design control | Yes | Partial | Partial |
| Images, tables & conditionals | Yes | Yes | Yes |
| Best for | Custom invoices, certificates, reports | Editable proposals & letters | Contracts, invoices, quotes |
| Explore | Explore | Explore |
If a document is the same shape every time but the details change, it is a candidate for templating.
Drop in line items, totals and customer details, then send a clean PDF per order.
HTML or Word to PDFMerge party names, dates and clauses into a legally formatted, locked PDF.
Word to PDFPersonalise names and dates at scale and export as PDF or PNG images.
HTML + JSONGenerate tailored proposals your sales team can still tweak in Word.
Word to DOCXLoop over data arrays to build tables, charts and multi-page statements.
HTML + JSONMail-merge style letters and application forms, on brand, every time.
Word to DOCXThe same three capabilities work across all three tools, so your documents stay dynamic, not static.
Inject logos, signatures, QR codes or product shots, passed as a URL or Base64 string and sized to fit.
Loop over an array to build line items, guest lists or schedules. Rows expand to match your data.
Show or hide whole sections based on your data: a "Paid" stamp, a discount block or a legal clause.
The Word tools offer the same with field types
image
table
conditional
and html.
A step-by-step walkthrough with real code examples for the Word tools, including how to choose between Handlebars {{placeholders}} and built-in Word fields, plus images, tables and conditional content.
Write {{tokens}} straight into the document text, fast and visible.
Bind to custom document-property fields managed inside Word.
We ensure that all document processing is handled securely in the cloud, adhering to industry-leading standards like ISO 27001, GDPR, and HIPAA. To enhance security even further, we can ensure that no files or data are stored on our servers and never leave your country.
Learn more about securityIt is the process of producing a finished document - like a PDF or Word file - by merging a reusable template with data. You design the layout once, then generate one document per record by sending different values each time, all through a single API call.
Use HTML + JSON to PDF when developers want full pixel control and PDF/PNG/JPG output. Use Word Template to DOCX when business users design in Word and need an editable result. Use Word Template to PDF when the design lives in Word but you ship a final, locked PDF.
You send a JSON object alongside the template. The HTML tool uses Handlebars {{ mustache }} syntax. The Word tools support two methods: filling Microsoft Word custom document-property fields, or replacing {{placeholders}} written directly in the text - including images, tables and conditional blocks.
Yes. All three tools support injecting images, building repeating rows or tables from arrays, and showing or hiding sections based on conditions - so documents adapt to each record rather than just swapping in text.
No. Document generation runs on ConvertAPI's cloud through a single REST request. There is no template engine, headless browser or Office install to maintain, and official SDKs are available for every major language.
The HTML tool returns PDF, PNG or JPG. The Word tools return an editable DOCX or a final PDF respectively. You choose the format that matches how the document will be used.