Api2Pdf is a document toolbox: three engines, Office conversion and PDF utilities on usage pricing. HTML to Image is the simpler shape for HTML or URLs to PDF and PNG, with templates included.
Disclosure: we built HTML to Image. We've kept this comparison honest because the alternative is search results full of low-effort listicles. Competitor pricing and features were checked on Api2Pdf's public site in July 2026.
| Feature | Api2Pdf | HTML to Image |
|---|---|---|
| Pricing model | $1 / month base plus usage fees | $9 / 1,000 credits, flat |
| Free tier | One month of free credit | 25 renders per month, ongoing, no card |
| Rendering engines | Chrome, wkhtmltopdf, LibreOffice | Current Chrome only |
| PDF output | Yes, from HTML, URLs and Office files | Yes (format: "pdf", A4 portrait) |
| Office file conversion | Yes (Word, Excel, PowerPoint) | No |
| PDF merging and tools | Yes, plus watermark and password tools | No |
| Image output | Yes (Chrome screenshots) | PNG from HTML, URLs and templates |
| Named templates | No | 25 |
| Output hosting | URL held for 24 hours | CDN URL that stays live |
| Best for | document pipelines mixing Office files and PDFs | HTML or URLs to PDF and PNG, without engine choices |
Stay with Api2Pdf when your pipeline is genuinely document-shaped. It converts Word, Excel and PowerPoint files through LibreOffice, merges PDFs, adds watermarks and passwords, extracts page ranges, generates barcodes and even converts HTML to DOCX and XLSX. It also lets you pick the engine per request, with wkhtmltopdf still available for legacy layouts alongside Headless Chrome. That breadth is the product, and we do not compete with it.
Switch to HTML to Image when the actual job is HTML or a URL becoming a PDF or a PNG. There is no engine to choose (everything renders in current Chrome), the format parameter is the only switch between image and document, and twenty-five named templates cover invoices, certificates and social cards without writing markup. Output lands on a CDN URL that stays live, not one that expires in 24 hours. For the full picture of what PDF mode does and does not do, see the HTML to PDF API page.
No engine decisions. Api2Pdf asks you to pick between Headless Chrome, wkhtmltopdf and LibreOffice endpoints, each with its own quirks. Here everything renders in current Chrome, so the PDF matches what the browser shows, and the same request shape returns a PNG when you drop the format field.
Output you can link to. Api2Pdf's file URLs are deleted after 24 hours, so every render needs a download-and-store step. Our renders live on the CDN for the life of a paid account, which for receipts, tickets and certificates is usually the whole storage story.
Templates and a permanent free tier. Twenty-five named templates render documents and cards from JSON, and the free tier is 25 renders every month rather than a one-month trial credit.
Breadth. Office file conversion, PDF merging, watermarking, password protection, page extraction, thumbnails, barcodes and HTML to DOCX or XLSX. If you need more than one of those, a single Api2Pdf integration replaces several tools.
Usage pricing at low volume. With a $1 monthly base plus small per-MB and per-second fees, a few hundred lightweight conversions a month can cost pennies. Flat plans only win once volume is steady.
Engine choice as a feature. Layouts built years ago for wkhtmltopdf render as they always did, without a migration to Chrome's rendering behaviour.
# Api2Pdf (HTML to PDF via Headless Chrome)
curl -X POST https://v2.api2pdf.com/chrome/pdf/html \
-H 'Authorization: your-api2pdf-key' \
-H 'Content-Type: application/json' \
-d '{"html": "<h1>Invoice #1042</h1>"}'# HTML to Image (HTML to PDF)
curl -X POST https://app.html2img.com/api/html \
-H 'X-API-Key: your-key-here' \
-H 'Content-Type: application/json' \
-d '{"html": "<h1>Invoice #1042</h1>", "format": "pdf"}'
Three concrete differences. The engine moves out of the URL: Api2Pdf encodes it in the path (/chrome/pdf/html) while here the endpoint is just /api/html with format: "pdf" in the body. Auth swaps a bare Authorization header for X-API-Key. And the response swaps a 24-hour FileUrl for a persistent url on the CDN. URL conversions map the same way, from /chrome/pdf/url to /api/screenshot.
There is no clean crossover point because the models differ. Api2Pdf bills $1 a month plus $0.001 per MB and $0.00019551 per second of compute, so cost tracks document weight and render time. HTML to Image bills flat: $9 for 1,000 renders, $25 for 3,000, with every render costing one credit. Light, occasional workloads will often be cheaper on Api2Pdf; steady volume with hosting included tends to favour flat credits. If you are also comparing subscription PDF services, the PDFShift comparison covers the credit-plan model.
No. Api2Pdf runs LibreOffice behind its API and converts Word, Excel and PowerPoint documents to PDF, alongside HTML-to-DOCX and HTML-to-XLSX conversion. HTML to Image takes HTML, CSS and URLs only. If Office files are part of your pipeline, Api2Pdf covers a job we do not attempt.
No. Api2Pdf offers PDF merging plus watermarking, password protection and page extraction as separate endpoints. HTML to Image returns one rendered document per request. If you need to stitch renders together, you would do that in your own code with a PDF library.
They are different shapes. Api2Pdf is pay-as-you-go: $1 a month base, $0.001 per MB of bandwidth and $0.00019551 per second of compute, which can work out very cheap at low or spiky volume. HTML to Image is flat: $9 a month for 1,000 renders, with a permanent free tier of 25 renders. Flat pricing is easier to forecast; usage pricing can be cheaper. Run your real numbers through both.
Api2Pdf returns a URL that holds the file for 24 hours, after which it is deleted, so you download and store it yourself. HTML to Image returns a URL on the i.html2img.com CDN that stays live for the life of a paid account, which often removes the storage step entirely.
The free tier covers 25 renders a month with no credit card. Try the API against your real data before deciding.
Twenty-five pre-built designs you can call with JSON, as a PNG or a PDF. No markup to write, no engine to pick.