Headless-Render-API vs SEO4Ajax (2026): which should you pick?

Pick Headless-Render-API if

• Fits if you run a Node.js or Next.js app and can add a middleware yourself
• Works for developers who also need screenshots or PDFs of pages from the same API

Look elsewhere if

• Watch out: going one request past 20,000 in a cycle moves the bill from $9 to $40
• Not for you if you want reports, as it's an API with no dashboard
• Tight if you use nginx, Apache, Ruby, Golang or IIS, whose integrations are examples and less well kept
• Tight if you stay free, at 500 requests a month and 15 an hour without a token
• Skip it if you can't edit your server, as setup is a middleware or proxy rule

Pick SEO4Ajax if

• Fits if you run a small JavaScript site under 1,000 pages and can edit its server config
• Works for sites that need search bots and social previews to see rendered pages

Look elsewhere if

• Watch out: a yearly commitment is still charged monthly, and leaving early costs the lesser of three months of fees or half of what remains
• Pricey if you want the SEO reports, which need Premium at $10 to $66 a month more on a yearly commitment
• Tight if you go over your pages, at $1.50 per 1,000 extra on Project
• Not for you if you run more than 3 sites on Project, as plans cap sites at 3, 5 or 10
• Watch out: the 99.9% uptime SLA is an extra $39 or $79 a month on Growth and Business

Headless-Render-API

• Billing is by API requests at the end of each 30-day cycle, so going just past 20,000 requests moves the bill from $9 to $40.
• Without billing details, use is capped at 500 requests a month.
• The nginx, Apache, Ruby, Golang and IIS integrations are offered as examples and are not as well maintained as the Node.js, Docker, Next.js and CloudFront ones.
• It is an API with no dashboard of reports; setup means adding middleware or a proxy rule to your server.

SEO4Ajax

• A yearly commitment is still charged monthly, and cancelling it early costs the lesser of three months of fees or half of what remains.
• Pages beyond the allowance cost $1.50 per 1,000 on Project, $1.00 on Growth and $0.50 on Business.
• SEO reports need the Premium version of each plan, which costs $10 to $66 a month more on a yearly commitment.
• Plans cap the number of websites at 3, 5 or 10, and a 99.9% uptime SLA is an extra $39 or $79 a month on Growth and Business.

Headless-Render-API

Pre-rendering for single-page apps

Proxy all requests, or only bots such as Googlebot and Twitterbot, through headless Chrome and get rendered HTML back for SEO and link previews.

Waits for data and keeps state

Rendering waits for XHR and WebSocket calls to finish, caches AJAX responses and can serialize app state into the HTML for the browser to pick up.

Screenshot API

Capture pages as PNG, WebP or JPEG, with options for device size, mobile viewport, high-DPI scale and cropping to an element.

PDF API

Print a page to PDF with page ranges, margins, paper size, landscape mode, background printing or a single page with no breaks.

Scrape API

Returns a rendered page's HTML, title, meta and Open Graph tags, links, status code and headers, with an optional screenshot.

Middleware and Docker server

A Node.js middleware and a ready-made pushstate server, run from npm or Docker, serve a build folder or an S3 bucket through the service.

SEO4Ajax

Dynamic rendering for bots

Pages are captured with a current version of Chrome and the cached snapshots are served to search engines such as Google and Bing and to social networks.

Server snippets and middleware

The console gives configuration snippets for Apache, Nginx and IIS, and there are middlewares for Express, Django, Rails and Java plus guides for Cloudflare and CloudFront.

Dedicated capture browsers

Each plan has dedicated browsers that capture pages in parallel; one browser averages about 200,000 captures a month, enough to refresh a Project site every 3 days.

Console metrics

Shows bot activity, cache freshness, duplicate pages and broken links for each site, with metadata exports to CSV.

Capture hooks and rewrite rules

Control how pages are captured and return HTTP errors or redirects to bots, page by page or by URL pattern.

SEO reports

Premium plans add reports on technical issues that can hurt indexing, such as broken links, duplicates and invalid hreflang tags.

Headless-Render-API

• Free$0

  Under 500 requests a month. Also the fallback tier if a card payment fails three times.

• Under 20,000 requests$9

  per month for under 20,000 requests, billed after use

  Charged at the end of each 30-day cycle; no rate limit once billing details are added.

• Under 100,000 requests$40

  per month for under 100,000 requests, billed after use

  The top flat tier. Above 100,000 requests the whole month is charged per request instead.

• 1 million requests$360

  per month for 1,000,000 requests, billed after use

  $0.00036 per request above 100,000 a month, so 1.5 million requests cost $540.

• 10 million requests$3,240

  per month for 10,000,000 requests, billed after use

  $0.000324 per request at this volume.

• 100 million requests$25,000

  per month for 100,000,000 requests, billed after use

  $0.00025 per request, so 150 million requests cost $37,500.

SEO4Ajax

• Developer$0

  1,000 pages and 2,500 snapshots a month, with community support.

• Project$29

  per month for 20,000 pages, yearly commitment ($39 monthly)

  Up to 3 websites, 1 dedicated browser and email support within 48 hours. The Premium version with SEO reports is $39 ($52 monthly).

• Growth$99

  per month for 100,000 pages, yearly commitment ($129 monthly)

  Up to 5 websites, 5 dedicated browsers and email support within 24 hours. The Premium version with SEO reports is $132 ($172 monthly).

• Business$199

  per month for 500,000 pages, yearly commitment ($249 monthly)

  Up to 10 websites, 10 dedicated browsers and email support within 24 hours. The Premium version with SEO reports is $265 ($332 monthly).

• Custom PlanCustom

  For more than 500,000 pages or 10 sites, or custom support, SLA or browser counts.

Headless-Render-API

No public discounts listed.

SEO4Ajax

• Annual discount

  Save 20% to 26% with a yearly commitment

  Project is $29 a month on a yearly commitment instead of $39 month to month, Growth $99 instead of $129, and Business $199 instead of $249.