Natural Language Processing Api
The best 50 Natural Language Processing Api AI tools - Free & Paid
Explore 50 AI for Natural Language Processing Api
AIMLAPI.com offers a unified API endpoint for over 400 AI models spanning chat, image, video, audio, voice, text, 3D, and OCR. It supports sandbox testing, granular access control, batch requests, and an OpenClaw runtime for secure, human‑in‑the‑loop workflows.
Freemium
GooseAI is a fast NLP-as-a-service tool that provides text completion/generation and question/answer tasks through an API.
Usage based
- $0.00011
DeepSeek API, available via Kie.ai, provides access to DeepSeek models R1 and V3 for complex reasoning and natural language processing.
Freemium
NaturalReader AI converts PDFs, Word, ePub, web pages, and OCR text into natural‑sounding audio in 90+ languages. It supports voice cloning, offline playback, mobile and Chrome extension access, and includes captions and dyslexia‑friendly fonts.
Freemium
Deepgram Voice AI offers real‑time and batch speech‑to‑text, text‑to‑speech, and voice‑agent APIs. It delivers low‑latency transcripts, natural‑sounding synthesis, and integrated conversation handling for contact centers, transcription, and podcasts, with cloud, on‑prem, and telephony support.
Freemium
A web‑based Microsoft AI TTS tool offering 330+ neural voices in 129 languages. Users can adjust rate, pitch, pauses, and style for news, scripts, or narration. Works across Chrome, Firefox, Edge, with an API for web integration.
Free
Sapling offers a language‑model API that delivers real‑time grammar corrections in enterprise workspaces and messaging platforms. Developers embed it into editors, CRMs, and customer‑service tools with a simple SDK/API, while the platform supports private cloud, encryption, PII redaction, SSO, and s
Freemium
- $25/mo
Langsearch is a web search API that enables natural language queries and semantic reranking for improved search accuracy. It offers real-time access to diverse information, making it suitable for AI agents and applications needing enhanced search capabilities.
Free trial
Talkpal is an AI‑powered language tutor supporting 80+ languages with interactive modes like speaking, writing, call, photo, and roleplay. It provides real‑time feedback on pronunciation, grammar, and vocabulary, personalizes practice, tracks progress, and offers certificate‑ready assessments.
Subscription
- $4.68/mo
Humanize AI converts AI‑generated text into natural, readable language while preserving meaning, keywords, and SEO value. It supports multiple languages, works on any device without registration, removes plagiarism, and evades detection systems.
Free
SpeechGen.io converts up to 2 million characters into high‑quality neural‑voice audio across 150 languages with 5,000 models. It allows voice, speed, pitch, volume control, SSML tags, background music, multi‑speaker tagging, downloadable formats, and a REST API.
Paid
- $4.99
Vapi is an AI tool that facilitates rapid voicebot development for various applications like customer support, sales, telehealth, etc. It provides features such as low-latency streaming, multilingual support, and customizable models to efficiently create sophisticated voice solutions.
Free trial
- $36
Hallo offers AI‑driven language proficiency tests in 60+ languages, delivering immediate CEFR‑aligned scores and detailed feedback on fluency, vocabulary, grammar, and pronunciation. It integrates with ATS for real‑time results and secure data handling.
Subscription
PlayAI turns text into natural‑sounding audio in 42+ languages using 800+ voices. Users adjust pitch, rate, volume, add SSML pronunciations, support multi‑speaker real‑time synthesis, voice cloning, and API integration for chatbots, streaming, IVR, e‑learning.
Free trial
- $29/mo
AI Humanizer transforms AI‑generated text into natural, human‑like prose, using NLP to restructure sentences and replace repetitive patterns while preserving meaning. It supports eight languages and processes up to 5,000 words per use, aiding writers, marketers, and professionals.
Subscription
Noiz AI is a text-to-speech and voice-cloning platform that captures and customizes voices, including tone, emotion, accent and pacing, supports multilingual dubbing and exports dubbing-ready tracks with an API for embedding and automating TTS.
Subscription
- $3.9/mo
Tinq.ai consolidates enterprise files—PDFs, slides, images, databases—into a secure, searchable layer. It syncs in real‑time, mirrors permissions, and exposes an OpenAI‑compatible endpoint, enabling AI models to retrieve up‑to‑date, cited insights across Slack, Teams, Salesforce, and more.
Subscription
- $15/mo
AI API is a unified interface that connects to 100+ AI models for text, code, image, video, and speech tasks via a single OpenAI-compatible endpoint. It simplifies switching between models without code changes, with built-in routing, failover, and monitoring for production-ready development.
Freemium
SharpAPI is a multifaceted AI tool for app development, encompassing e-commerce, sentiment analysis, content automation, and HR tech support. It provides features such as product intros, summarization, and job description generation across multiple industries.
Freemium
The Speak AI tool is a language data analysis and research platform with transcription, data analysis, and sentiment analysis capabilities for various types of media.
Free trial
Chat & Ask AI combines web search, image generation, link analysis, document chat, and YouTube summarization in one interface. It offers up‑to‑date answers, multilingual support, file uploads, and a prompt library, powered by GPT‑5.2, Gemini, Claude, and Stable Diffusion XL.
Free
Rehumanize.io is an AI humanizer that rewrites machine-generated text to sound natural while preserving core meaning and technical terms. It offers batch processing, multilingual support, and style adjustments to remove AI patterns and improve fluency for content creators.
Free
Voice.ai offers cloud‑and on‑prem AI voice agents for calls, scheduling, and queries, supporting 15+ languages. It provides text‑to‑speech, 10‑second voice cloning, real‑time voice change, noise filtering, and integrates with Salesforce, HubSpot, Zendesk, Slack. APIs and SDKs enable scalable deploym
Freemium
- $5/mo
Napi Bot offers a single‑command API that links Google Assistant to smart‑home devices and GPT services. With clear docs and API‑key authentication, developers can trigger device actions or generate responses, enabling automated home control and conversational flows.
Paid
Lingvanex delivers on‑premise machine translation and speech‑to‑text for over 100 languages, with APIs, SDKs, desktop and mobile apps, enabling secure, offline multilingual content processing, summarization, and data anonymization for business intelligence and compliance.
Freemium
Puretalk AI® is a conversational AI platform that offers voice agents and chatbots for improved customer interactions. It features multi-language text-to-speech, automation for customer service, and easy integration with existing tools for enhanced workflow efficiency.
Free trial
Eden AI offers a single API that consolidates LLMs, vision, OCR, speech, translation, and more from Meta, Mistral, AWS, Azure, Google, and OpenAI. It provides smart routing, fallback, cost/latency selection, batch processing, caching, and multi‑API key management.
Subscription
Detecting‑AI scans text in 50+ languages, marking AI‑generated sentences with probability scores. It integrates with Chrome, Moodle, Zapier, and offers an API, delivering up to 98% accuracy and low false‑positives while protecting user privacy.
Freemium
- $7/mo
Nofiltergpt is an AI chat tool that offers anonymous and unfiltered conversations. It ensures data security through local cloud storage and AES encryption, supports multiple languages, and provides a RESTful API for seamless integration.
Free trial
OpenAI's advanced conversational AI, fueled by GPT-3.5-turbo, delivers fluent text conversations through sophisticated natural language processing. Adjustable max tokens, message size, and integration with Azure/Google APIs enhance deployment, while multilingual support ensures customizable user ex
Freemium
Whisper API delivers fast, accurate speech‑to‑text with speaker diarization, translation, and summary in 100+ languages, supports diverse audio formats, is OpenAI‑compatible, and enables quick developer integration for streamlined workflows.
Freemium
- $0.15
Palabra.ai is a real-time voice translation platform that provides live speech-to-text transcription and simultaneous interpretation across dozens of languages. Its APIs and features enable multilingual meetings, captions, and integration into apps for collaboration, support, and accessibility.
Free trial
- $150/mo
SpeakPal AI offers real‑time conversation practice in 30+ languages with adaptive tutoring, instant grammar correction, and pronunciation coaching. Users can download lessons, earn QR‑coded certificates, and educators access teen‑safety mode, all syncing across web, iOS, and Android.
Free trial
Nex AI ingests, validates, and streams structured and unstructured data to AI agents or ERP/CRM systems, offering compliance checks, risk flagging, fraud detection, instant alerts, audit trails, and secure API integration with multiple data platforms.
Subscription
Hume AI offers emotion‑intelligent text‑to‑speech, real‑time speech‑to‑speech, and expressive voice cloning across 100+ languages. Developers use TypeScript, Python, .NET, or Swift SDKs to build voice‑design, stage‑direction, and emotion‑analysis features for content creation.
Freemium
- $3/mo
Humanize AI Text converts AI‑generated content into natural, human‑sounding prose while preserving meaning. It works browser‑free, supports unlimited words in multiple languages, and produces plagiarism‑free output that passes AI‑detection tools.
Freemium
AI Studio lets developers generate code, SQL, regex, and shell commands from plain‑English prompts across multiple languages, adding type annotations, calculating complexity, explaining code, creating tests, and enabling real‑time collaboration with exportable workspaces.
Freemium
Resemble AI delivers real‑time voice conversion and cloning from brief samples, supports 149+ languages, lets users edit audio via text, and includes deep‑fake detection, watermarking, and API integration for secure, ethical use.
Freemium
- $0.006
All‑in‑one platform integrating GPT‑4o, Claude, Gemini, and others for unified text, image, video, and document AI. Offers summarizing, translation, prompt templates, workflow tools, quiz creation, SCORM export, web search, subtitles, dubbing. SOC II‑compliant with field‑level encryption and data is
Subscription
- $8/mo
A platform for AI-powered text and image generation, offering tools for content creation, natural language processing, machine learning, text summarization, image recognition, and visual search.
Freemium
- $30/mo
API-first platform that provisions and manages email inboxes for AI agents, offering REST endpoints, typed SDKs and webhooks for two-way threaded email, attachments, semantic search and structured data extraction (documents, invoices, OTPs) plus delivery and spam events.
Freemium
- $20/mo
AI Humanizer turns AI‑generated text into natural language while preserving meaning. It detects AI origin with leading systems, supports 50+ languages and long documents, offers Chrome extension and API, and lets users select pre‑built models or clone their own style.
Subscription
- $8.25/mo
LingoChamp is an AI‑powered platform offering personalized courses in English, Spanish, Japanese, Korean, German, and French. It creates tailored study plans, provides AI coaching, native tutor group sessions, global chat practice, business English modules, and real‑time pronunciation feedback.
Free
WriteHuman AI Humanizer refines ChatGPT, Claude, Gemini, and Deepseek outputs into natural prose, preserving the author’s voice. It offers readability scanning, AI detection, multiple variations, word‑count control, and web/API access for batch workflows.
Freemium
- $0.75/mo
WebScraping.AI offers a single API that retrieves clean HTML, plain text, or JSON from any URL, handling JavaScript-heavy pages, proxies, CAPTCHAs, and retries. Users can query, extract fields, generate summaries via prompts, and integrate with SDKs or workflow tools.
Subscription
- $29/mo
AssemblyAI offers real‑time and batch speech‑to‑text transcription across 99+ languages, featuring speaker diarization, sentiment analysis, and language identification. It supports medical terminology, PII redaction, and custom prompts for precise conversational insights.
Freemium
- $0.37