AdSize VS DynamicDocumentAPI

AdSize's answer

AdSize is a free, no-signup reference for advertising and social media creative sizes that stays genuinely current — and goes well beyond a plain size chart. Every dimension, max file weight, accepted format and video spec is cross-checked against each platform's official documentation and carries a data-confidence indicator. Each size has its own page with a live, aspect-accurate preview (feed post, 9:16 phone with safe zones, cover, banner), so you catch cropping before you export. It covers 30 ad and social platforms across 310 sizes, in 6 languages, and adds tools most charts don't: side-by-side platform comparison, an ad-terminology glossary, and geo profiles for 241 countries. No ads, no tracking, no account.

DynamicDocumentAPI's answer:

It covers the whole path from data to finished document in one API: you design a template in a visual or HTML editor (or send raw HTML, CSS or Markdown), send JSON, and get a PDF or image back. The same service also creates e-invoices (XRechnung, EN 16931, Factur-X / ZUGFeRD) that are validated against the official rules before they are returned, and can embed them in the PDF. Rendering is deterministic: the same template and data always give the same document, laid out by a headless browser, with no AI model generating content. Everything runs in the EU (Germany). It also ships an MCP server, so AI agents like Claude and ChatGPT can render documents directly.

AdSize's answer

• Accuracy you can trust — sourced from official platform docs with a confidence indicator, not copied from stale blog posts.
• Live previews — every size rendered to scale with safe zones, so nothing gets cropped on export.
• More than sizes — compare two platforms side by side, decode jargon in the glossary, and check any market with geo profiles before you spend.
• Truly free & private — no registration, no ads, no tracking, no personal data collected.
• Multilingual & fast — 6 languages, instant search, clean mobile UI, kept up to date for the current year.

DynamicDocumentAPI's answer:

Most document APIs do one thing: convert HTML to PDF, or fill templates. Dynamic Document API does both, adds image templates, PDF merging and validated e-invoices, and offers them through a REST API, SDKs for Node and Python, Zapier, Make, n8n and an MCP server for AI agents. Data is processed and stored in the EU only, files come back as signed links that expire, and storing nothing at all is a supported option. Pricing is predictable: one published credit table, the same core features on every paid plan and a spend cap you control. We also publish a render-time benchmark with its method and raw data, so you can check our speed instead of trusting a claim. The free plan includes 50 renders a month without a credit card.

AdSize's answer

Designers and marketers who produce ad and social creatives — in-house teams, agencies and freelancers — plus media buyers, affiliate/performance marketers and social media managers. Essentially anyone who needs the exact, current spec for a platform before exporting a creative, and — via the geo guide — anyone planning campaigns across different markets.

DynamicDocumentAPI's answer:

Developers and product teams whose software has to send documents: invoices after a payment, certificates after a course, reports, labels and statements. Typical users are SaaS companies, marketplaces, e-commerce and learning platforms. A second group are businesses in Germany and the EU that need compliant e-invoices (XRechnung, ZUGFeRD) for the German B2B e-invoicing mandate and public-sector buyers. No-code builders use it through Zapier, Make and n8n, and teams building AI agents use the MCP server.

AdSize's answer

AdSize grew out of a recurring frustration: creative sizes are scattered across dozens of platform help pages that change without notice, and most "cheat sheets" online are outdated within months. The goal was one always-current, free reference — every size verified against the official source, with live previews so you see exactly what you're building. It expanded from a size table into a full toolkit (comparison, glossary, per-country geo profiles) and multiple languages, built to stay fast, privacy-friendly and free.

DynamicDocumentAPI's answer:

Almost every product eventually needs to produce documents, and most teams end up building their own rendering stack: a headless browser, fonts, page breaks, storage and retries. It works until an invoice splits a table row or a certificate shows the wrong date, and then it becomes a support ticket. We built Dynamic Document API to be that layer for them: templates, rendering and delivery as one service, hosted in Europe, treating pagination, fonts and formatting as engineering problems rather than edge cases. When e-invoicing became mandatory for B2B in Germany, we added validated XRechnung and ZUGFeRD output, and with AI agents producing more paperwork, an MCP server followed.

DynamicDocumentAPI's answer:

Rendering runs in Rust workers that drive headless Chromium over the DevTools protocol, with MiniJinja for templates. The API and control plane are built with Django and Django REST Framework, with Celery, PostgreSQL, Valkey and NATS JetStream for queues and events, and S3-compatible object storage for files. PDF/A output is checked with veraPDF and e-invoices with the official KoSIT validator. The dashboard and website are built with Next.js. Everything runs on Kubernetes in data centres in Germany.

DynamicDocumentAPI's answer:

Dynamic Document API is a young product. Our users are mostly developers and small SaaS teams, and we don't name customers without their permission.