What each moderation API actually classifies (and the marketing copy to ignore)
**OpenAI Moderation** is the omni-moderation-latest endpoint at https://platform.openai.com/docs/guides/moderation. It accepts text and image inputs, returns a flag plus per-category scores across thirteen categories (sexual, sexual/minors, harassment, hate, illicit, self-harm, violence and their variants), and is free under standard OpenAI rate limits. The marketing claim to ignore: it does not detect spam, scam links, deepfakes, weapons brand names, or AI-generated images. It is a baseline LLM-policy filter, not a full trust and safety stack.
**Perspective API** from Jigsaw at https://perspectiveapi.com/ is the most-cited toxicity API on the planet, used by The New York Times comments, The Wall Street Journal, and Reddit's automod. It returns 0-1 scores across six production attributes (toxicity, severe toxicity, identity attack, insult, profanity, threat). Text-only, free under a 1 QPS quota, with higher quotas via dashboard application. 'Identity attack' was retrained in 2024 to reduce demographic bias but still over-flags reclaimed slurs in LGBTQ and Black English contexts. Tune thresholds per surface, not globally.
**Azure AI Content Safety** at https://azure.microsoft.com/en-us/pricing/details/cognitive-services/content-safety/ covers text and image across four harm categories (hate, sexual, violence, self-harm) at four severity levels each, plus a separate Prompt Shields endpoint for jailbreak detection and a Groundedness Detection endpoint for hallucination flagging. Pricing runs roughly $0.38 per 1k text records and $1.00 per 1k images at Standard tier. Azure also ships Custom Categories in Preview — not GA in every region, so do not bet a launch on Preview SKUs.
**AWS Comprehend Toxicity Detection** at https://aws.amazon.com/comprehend/pricing/ handles text moderation across seven labels (graphic, harassment_or_abuse, hate_speech, insult, profanity, sexual, violence_or_threat) at roughly $0.0005 per 100 characters. For images and video, **Rekognition Content Moderation** at https://aws.amazon.com/rekognition/pricing/ bills roughly $0.001 per image and $0.10 per minute of video in the first million units. Rekognition's celebrity recognition feature was deprecated in 2023 for several use cases — verify which sub-features are GA in your region.
**Google Cloud Natural Language** moderation at https://cloud.google.com/natural-language/pricing offers a moderateText endpoint at roughly $1 per 1,000 calls, plus Vertex AI safety filters baked into every Gemini API call for free. The DLP API handles PII redaction at roughly $1 per 1,000 records. Coverage is narrower than Azure or AWS — best as an add-on for existing Vertex AI customers, not a primary choice.
**Hive Moderation** at https://hivemoderation.com/pricing and **Sightengine** at https://sightengine.com/pricing are the specialists. Hive sells 30+ classifier models including deepfake detection, weapons brand recognition, OCR-aware moderation, and demographic estimation — custom pricing lands roughly $1-2 per 1,000 calls. Sightengine ships 30+ classifiers including deepfake, AI-generated content, and scam-link analysis on a transparent tier ladder. Both win when your needs go past the four standard harm categories.