AWS Comprehend vs TextLens API

AWS Comprehend is a powerful NLP service — but it has no readability scoring. If you need Flesch-Kincaid grades, SMOG, or consensus readability scores alongside sentiment analysis, TextLens API fills that gap without IAM roles, VPCs, or per-character pricing.

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Feature comparison

Feature AWS Comprehend TextLens API
Readability formulas None 8 (Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, ARI, Dale-Chall, Linsear Write, consensus)
Sentiment analysis ✓ (mixed/positive/negative/neutral) ✓ (AFINN score + label)
Entity recognition ✓ (people, places, orgs, etc.) ✗
Keyword extraction ✗ ✓ TF-IDF with relevance scores
SEO scoring ✗ ✓
Pricing model Per character ($0.0001/unit after free tier) Per request (flat monthly tiers)
Free tier 50K units/mo for 12 months 1,000 req/mo (no expiry)
Setup required AWS account, IAM role, region selection API key (email signup)
Authentication AWS Signature V4 (sigv4) X-API-Key header
SDK dependency boto3 (Python) or AWS SDK HTTP only (curl, fetch, any language)
Minimum request size 1 character No minimum
Languages supported 100+ Any (text is text)

The code

AWS Comprehend Python

import boto3

client = boto3.client(
    'comprehend',
    region_name='us-east-1',
    aws_access_key_id=AWS_ACCESS_KEY_ID,
    aws_secret_access_key=AWS_SECRET_KEY
)

response = client.detect_sentiment(
    Text=text,
    LanguageCode='en'
)
# sentiment: POSITIVE | NEGATIVE | NEUTRAL | MIXED
print(response['Sentiment'])

# AWS Comprehend has no readability scoring.
# You would need a separate library (textstat, etc.)
# and a separate API call for each analysis type.

TextLens API Python

import requests

response = requests.post(
    'https://api.ckmtools.dev/v1/analyze',
    headers={'X-API-Key': TEXTLENS_KEY},
    json={'text': text}
)
result = response.json()

# Readability + sentiment in one call
print(result['readability']['consensus_grade'])  # Grade 8
print(result['sentiment']['label'])              # positive
print(result['keywords'][0]['term'])             # 'content analysis'

AWS Comprehend requires IAM credentials, a regional endpoint, and a separate library for readability scoring. TextLens API returns readability, sentiment, and keywords from one POST request with an API key.

Which one to use

Use AWS Comprehend when:

  • You need named entity recognition (people, organizations, places)
  • You're processing medical text (Comprehend Medical)
  • You need 100+ language support for sentiment
  • You're already deep in the AWS ecosystem

Use TextLens API when:

  • You need readability grades (Flesch-Kincaid, SMOG, etc.)
  • You want keyword extraction (TF-IDF)
  • You need simple flat pricing without per-character math
  • You don't want to manage IAM roles for a text analysis endpoint
  • You're building in a language without a mature AWS SDK

Pricing

AWS Comprehend charges $0.0001 per unit (100 characters) after a 12-month free tier of 50K units/month. For a 1,000-word article (~5,500 characters), that's approximately $0.0055 per API call. TextLens API charges a flat monthly rate: Free (1,000 req/mo), Starter $9/mo (25,000 req), Pro $29/mo (100,000 req), Enterprise $99/mo (500,000 req).

For content teams running readability checks on 100 articles/week (~4,400 req/mo), TextLens API Starter tier ($9/mo) compares to approximately $24/mo on AWS Comprehend for sentiment alone — and Comprehend still has no readability scoring.

Pricing estimates are approximate and subject to change. Check aws.amazon.com/comprehend/pricing for current AWS rates.

Get Early Access

TextLens API is in development. Join the waitlist to get notified at launch.

From the team behind textlens — 96 npm downloads this week.

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