Text Processing APIs: Analyze, Transform, and Understand Text at Scale

From content moderation to readability scoring, text processing is a core requirement for SaaS products, content platforms, and internal tools. Building NLP pipelines from scratch requires ML expertise and significant compute. Text processing APIs give you production-ready NLP capabilities through simple REST calls.

Why use a text processing API?

Add NLP features (sentiment, language detection, keyword extraction) without training models
Moderate user-generated content with profanity detection and severity scoring
Convert between formats (Markdown, HTML, plain text) with consistent, clean output
Measure content readability with established metrics like Flesch-Kincaid and Gunning Fog
Process text in 100+ languages without building multilingual support from scratch

Text Processing APIs

11 APIs available in this category. All included in every plan.

NLP Tools APIFeatured

Language detection, sentiment analysis, keyword extraction

Email Template API

Generate responsive HTML email templates

Profanity API

Detect and filter profanity with severity scoring

Language Detect API

Detect the language of text with confidence scoring

Readability API

Analyze text readability with Flesch-Kincaid, Gunning Fog, and more

Markdown API

Convert between Markdown and HTML

Markup API

Convert between HTML, Markdown, and plain text

Diff Tools API

Compare text differences line by line or character by character

TextTools API

HTML sanitizer, text similarity, timezone conversion

Lorem Ipsum API

Generate placeholder text

Slugify API

Generate URL-friendly slugs from text

How to process text with Van Moose

Choose the right text API

NLP Tools for sentiment and keywords, Profanity API for content moderation, Language Detect for multilingual routing, Readability API for content scoring.

Send your text

POST the text content to the API endpoint. Most text APIs accept strings up to 100KB, which covers articles, comments, reviews, and product descriptions.

Use the structured results

Each API returns JSON with scores, labels, and extracted data. Integrate into content workflows, moderation queues, or analytics dashboards.

Quick example

NLP Tools API

curl -X GET \
  "https://nlptools.vanmoose.cc" \
  -H "Authorization: Bearer vm_live_YOUR_API_KEY"

Replace vm_live_YOUR_API_KEY with your actual API key from the dashboard.

Frequently asked questions

How does sentiment analysis work?+

The NLP Tools API analyzes text and returns a sentiment score (-1 to 1) along with a label (positive, negative, neutral). It also extracts keywords and named entities. Works well for product reviews, social media posts, and customer feedback.

Can I filter profanity in multiple languages?+

The Profanity API primarily supports English with strong accuracy. It returns matched words, severity scores, and a cleaned version of the text. For other languages, combine with the Language Detect API to route content to language-specific moderation.

What readability metrics are available?+

The Readability API calculates Flesch-Kincaid Grade Level, Flesch Reading Ease, Gunning Fog Index, Coleman-Liau Index, SMOG Index, and Automated Readability Index. It also provides word count, sentence count, and average words per sentence.

Can I convert Markdown to HTML and back?+

Yes. The Markdown API converts Markdown to HTML and HTML to Markdown. The Markup API extends this with plain text conversion and HTML sanitization. Both handle tables, code blocks, and common Markdown extensions.

Start building with Text Processing APIs

Get 500 free requests/month. No credit card required. All 11 APIs in this category included.

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