DevNestro

Free Online Tools

Search the list, then open a tool. The full catalog is also on Features. Each item has a matching guide on Articles. Most tools run in your browser. Use Contact if a page is broken or if you need to report a File Share or Secure Note link.

Text Tools

Word Counter

Count words, characters, sentences, paragraphs, and reading time as you type.

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Text Tools

Character Counter

Track characters and words against limits for bios, SMS, and meta descriptions.

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Text Tools

Case Converter

Switch text to lowercase, UPPERCASE, Title Case, Sentence case, or Capitalize Each Word.

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Text Tools

Remove Duplicate Lines

Deduplicate lists, trim whitespace, drop blank lines, and sort the result.

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Productivity

Online Notepad

Draft text that auto-saves in this browser. Copy, download .txt, or clear.

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Calculators

Age Calculator

Find exact age in years, months, and days, plus the next birthday.

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Calculators

Percentage Calculator

Find a percent of a number, reverse percentages, increase, decrease, and difference.

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Calculators

Discount Calculator

Work out sale prices from a discount, an extra discount, and optional sales tax.

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Calculators

Savings Goal Calculator

Calculate how much you need to save regularly to reach a financial goal.

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Calculators

Zakat Calculator

Estimate Zakat on eligible assets using commonly used calculation principles.

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Business Tools

Profit Margin Calculator

Calculate profit, margin, markup and selling price for products or services.

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Calculators

Date Difference Calculator

Count years, months, days, weeks, and weekdays between two dates.

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Conversion Tools

Unit Converter

Convert length, weight, temperature, area, volume, speed, data, and time.

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Conversion Tools

File Size Converter

Convert bytes, KB, MB, GB, and TB using decimal (1000) or binary (1024) units.

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Conversion Tools

Currency Converter

Convert currencies with recent Frankfurter reference exchange rates, swap, and history.

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File Tools

File Share

Share files up to 16 GB with a secure link that automatically expires after 24 hours.

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Productivity

Online Screen Recorder

Record your screen, tab, or window with optional microphone and webcam. Download locally or share for 24 hours.

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Productivity

Script to Video Maker

Turn a script into a captioned video with local Auto Voice, an uploaded voice-over, or captions only.

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Productivity

AI Book Marketing Video Generator

Create book trailers, BookTok clips, and launch teasers from your cover and blurb. Standard composer works without Veo.

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Audio Tools

Text to Speech

Convert text or documents into natural speech using multiple voices directly in your browser.

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Audio Tools

Video & Audio Text Extractor

Extract spoken words and on-screen text from video or audio in your browser. Download TXT, SRT, and VTT.

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Document Tools

OCR

Extract editable text from images, screenshots and scanned PDFs directly in your browser.

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Developer Tools

Universal Data Converter

Convert structured data between JSON, CSV, XML and YAML.

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Data Tools

CSV / Excel Data Cleaner

Clean CSV and Excel files by removing duplicates, empty rows, whitespace and inconsistent values.

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Developer Tools

Text & File Diff Checker

Compare text, code or files and clearly see what changed.

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Developer Tools

URL Toolkit

Parse, build, encode, decode and clean URLs from one convenient tool.

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SEO Tools

SEO & Social Preview Checker

Preview how a webpage may appear in search engines and social platforms and check common metadata.

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SEO Tools

Meta Tag Generator

Generate title, description, canonical, robots, Open Graph, and Twitter meta tags with informational length tips.

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SEO Tools

Schema Markup Generator

Build Article, FAQ, Product, Organization, and other JSON-LD blocks. Validates JSON — not rich-result guarantees.

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SEO Tools

Robots.txt Generator

Create User-agent, Allow, Disallow, and Sitemap groups, including crawler-specific rules.

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SEO Tools

Robots.txt Tester

Test a path and user-agent against robots.txt with longest/specific rule matching.

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SEO Tools

XML Sitemap Generator

Build sitemap.xml from a URL list or CSV/text upload with loc and optional lastmod. No crawl in V1.

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SEO Tools

Sitemap Validator

Validate sitemap XML for root element, duplicates, missing loc, size, and nested indexes. XXE disabled.

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SEO Tools

Redirect Checker

Inspect public redirect chains with status codes, loop detection, and HTTP→HTTPS upgrades.

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SEO Tools

HTTP Header Checker

Review status, cache, CSP, HSTS, and related headers as Present, Missing, or Needs Review — never “secure”.

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SEO Tools

Hreflang Tag Generator

Generate alternate hreflang link tags from language/region rows with optional x-default.

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SEO Tools

Canonical URL Checker

Safely fetch a page and inspect HTML and HTTP Link canonicals for common issues.

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SEO Tools

AI Crawler Checker

Compare robots.txt against a verified AI crawler registry. Preferences only — not a hard guarantee.

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Security Tools

File Hash & Integrity Checker

Calculate file checksums and verify that a downloaded file matches an expected hash.

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Productivity

Time Zone Meeting Planner

Compare time zones and find convenient meeting times for people in different locations.

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Design Tools

Color & Accessibility Checker

Check color contrast, convert color formats and preview accessible text and interface combinations.

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Privacy & Trust

AI Prompt Privacy Checker

Detect sensitive information in AI prompts and create a safer version before sharing it with an AI service.

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Privacy & Trust

Privacy Redactor

Find and remove personal or sensitive information before sharing text.

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Privacy & Trust

Secret Leak Inspector

Scan logs, .env, JSON, and YAML for API keys, tokens, passwords, and connection strings, then create a safe copy.

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Privacy & Trust

Stack Trace Safe-Share Cleaner

Redact usernames, home folders, hosts, and common secrets from stack traces before you paste them into a ticket.

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Privacy & Trust

Photo Metadata Cleaner

View hidden photo metadata and remove private information such as GPS location before sharing.

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Privacy & Trust

Screenshot Privacy Redactor

Blur, pixelate or hide sensitive information in screenshots before sharing them.

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Privacy & Trust

Document Privacy Cleaner

Inspect documents for potentially revealing metadata and create a cleaner copy before sharing.

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Privacy & Trust

Content Credentials Checker

Inspect media for Content Credentials and provenance information when available.

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Privacy & Trust

AI Image Detector

Analyze an image for AI-generation signals, provenance information, metadata and forensic indicators directly in your browser.

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Privacy & Trust

Scam Message & Link Checker

Check messages and links for common scam, phishing and impersonation warning signs.

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Privacy & Trust

Encrypted One-Time Secure Note

Share temporary encrypted text using an expiring or one-time link.

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Image Tools

Image Compressor

Compress JPG, PNG, and WebP in the browser. Compare original and compressed size.

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Image Tools

Image Resizer

Resize by width, height, or percent. Instagram, YouTube, Facebook, and LinkedIn presets.

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Image Tools

Crop Image

Interactive crop with zoom, rotate, and 1:1, 4:3, 16:9, or 9:16 ratios.

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Image Tools

JPG to PNG

Convert a JPEG photo to PNG in your browser.

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Image Tools

PNG to JPG

Convert PNG to JPG with quality control and a background colour for transparent areas.

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Image Tools

WebP Converter

Convert WebP to JPG or PNG, and JPG or PNG to WebP.

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Generators

Password Generator

Create a strong random password with length, letters, numbers, and symbols.

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Generators

Password Strength Checker

Rate a password as Weak, Fair, Good, or Strong from length, variety, and patterns.

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Generators

Random Number Generator

Draw random integers from a range, with or without duplicates.

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Generators

Random Name Picker

Pick one or more names from a list for classrooms, giveaways, and meetings.

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Productivity

Decision Wheel

Spin a wheel of names or choices. Remove the winner or reset the list.

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Generators

QR Code Generator

Make QR codes for URLs, text, email, phone, SMS, and Wi-Fi. Download PNG or SVG.

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Developer Tools

JSON Formatter, Validator & Viewer

Format, validate, minify, repair, search and explore JSON directly in the browser.

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Developer Tools

JSON to Code Generator

Generate C#, TypeScript, Java, Python, or Go types from a JSON sample in the browser.

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Developer Tools

XML Formatter, Validator & Viewer

Format, minify, validate, search, and explore XML with a tree and XPath tester. DTDs are blocked.

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Developer Tools

YAML Formatter, Validator & Viewer

Format and validate YAML in the browser. Duplicate keys are reported. Unsafe tags are rejected.

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Developer Tools

Code Formatter & Beautifier

Format JavaScript, TypeScript, HTML, CSS, Markdown, GraphQL, JSON, XML, and YAML in the browser.

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Developer Tools

Base64 Encoder

Encode and decode Base64 without sending data to a server.

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Developer Tools

GUID Generator

Generate RFC-compliant GUIDs for local development work.

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Developer Tools

Webhook Signature Playground

Generate and verify HMAC-SHA-256, SHA-384, and SHA-512 signatures in the browser. The secret is not uploaded.

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Developer Tools

Regex Safety & Performance Inspector

Flag nested quantifiers and backtracking traps, then test matches in a worker with a timeout so the tab stays responsive.

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AI & Documents

AI Usage Disclosure Generator

Draft a plain-language disclosure for AI-assisted articles, images, videos, social posts, research, and reports.

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AI & Documents

AI Task Specification Builder

Turn a rough request into Objective, Inputs, Constraints, Output, Quality Criteria, Edge Cases, Validation, and Examples.

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PDF Tools

Merge PDF

Combine PDFs in the browser. Reorder, remove, and download one file.

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PDF Tools

Split PDF

Extract pages with ranges such as 1-3,7,9-12. Download a new PDF.

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PDF Tools

JPG to PDF

Put JPEG photos on Auto, A4, or Letter pages with margins and orientation.

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PDF Tools

PDF to JPG

Render PDF pages to JPEG. Download one page or all pages as a ZIP.

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PDF Tools

PDF Editor

Edit PDF files online by adding text, images, signatures, drawings, highlights, shapes, and page changes directly in your browser.

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PDF Tools

PDF Intelligence

Summarize long articles or PDFs into bullets, and translate PDFs while keeping layout.

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AI & Documents

Private PDF Chat

Ask questions about a PDF and find answers from the document.

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Career Tools

Resume Job Match Checker

Compare a resume with a job description and identify matching and missing skills.

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Calculators

Bill & Group Expense Splitter

Split a bill equally or by item, add tax, service, and tip, then see who pays whom. No loans or interest.

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Productivity

Calendar Event Maker

Create an .ics event with an IANA time zone, all-day dates, recurrence, and reminders. No calendar sign-in.

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Document Tools

Document Expiry Tracker

Track names and expiry dates with 7 to 180 day reminders. Download ICS, CSV, or JSON. ID numbers are not required.

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Productivity

Emergency Card

Optional contact fields as a local QR code. Anyone who scans it can read the same text. PNG or PDF. No server storage.

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File Tools

File Renamer

Rename many files with a preview table and templates. Download a ZIP. Only names, types, dates, and sizes are used.

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File Tools

Universal File Inspector

Upload a file to see type, size, metadata summary, and recommended tools or Smart Workflows. Processed in your browser.

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Productivity

Home Inventory

List rooms and household items in this browser. Optional photos stay in IndexedDB. Not an insurance valuation.

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Document Tools

Document Scanner

Turn a photo of a paper document into a clean, straightened scan.

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Image Tools

Passport & ID Photo Maker

Create properly sized passport, visa and ID photos from an existing photo directly in your browser.

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Document Tools

Receipt & Invoice Extractor

Extract merchant, date, lines, and totals from a receipt photo. You review every field. Download CSV, XLSX, or JSON.

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Productivity

Screenshot Guide Maker

Turn screenshots into a numbered step-by-step guide and download PDF, HTML, or ZIP.

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Gemini AI Tools

Gemini AI Chat

Chat with Google Gemini. Messages are sent to Google. Not processed locally.

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Gemini AI Tools

AI Writer

Draft emails and articles with Gemini. Briefs are sent to Google.

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Gemini AI Tools

AI Summarizer

Summarize pasted text with Gemini. The source is sent to Google.

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Gemini AI Tools

AI Rewriter

Rewrite text in another style with Gemini. The original is sent to Google.

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Gemini AI Tools

AI Proofreader

Proofread a draft with Gemini. The draft is sent to Google.

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Gemini AI Tools

AI Translator

Translate text with Gemini, including Urdu and Arabic. Source is sent to Google.

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Gemini AI Tools

Structured Data Extractor

Extract JSON fields from text with Gemini. The source is sent to Google.

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Gemini AI Tools

AI Code Assistant

Ask coding questions with Gemini. Snippets are sent to Google. Review every suggestion.

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Gemini AI Tools

AI Document Analyzer

Upload a PDF or document to Gemini for a summary, dates, or custom questions. Files are sent to Google.

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Gemini AI Tools

Gemini PDF Chat

Ask Gemini questions about an uploaded PDF. The file is sent to Google. Not the local Private PDF Chat.

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Gemini AI Tools

Multi-File Comparer

Compare two or more documents with Gemini. Files are sent to Google. Not legal advice.

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Gemini AI Tools

Gemini File Search

Index documents in a temporary Gemini File Search store and ask grounded questions. Cloud AI.

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Gemini AI Tools

Long Document Analyzer

Analyze a long pasted source or large file with Gemini. Content is sent to Google.

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Gemini AI Tools

AI Image Analyzer

Describe a photo or screenshot with Gemini. The image is sent to Google. Not a forensic report.

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Gemini AI Tools

AI Image Text Extractor

Read visible text in a photo with Gemini vision. AI-assisted extraction, not the local OCR tool.

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Gemini AI Tools

AI Alt Text Generator

Draft alt text or a longer description with Gemini. Edit before you copy. Image is sent to Google.

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Gemini AI Tools

AI Image Generator

Generate an image from a prompt with Gemini. Prompts go to Google. Limited to 3 per hour.

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Gemini AI Tools

AI Image Editor

Upload a photo and describe a change for Gemini. Not pixel-perfect. The image is sent to Google.

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Gemini AI Tools

AI Audio Analyzer

Summarize a recording with Gemini. The audio is sent to Google. Not a forensic transcript.

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Gemini AI Tools

Gemini Audio Transcriber

Transcribe speech with Gemini. Audio is sent to Google. Not the local Whisper extractor.

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Gemini AI Tools

Gemini Text to Speech

Generate speech from text with Gemini TTS. Text is sent to Google. Not the local browser voices.

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Gemini AI Tools

Live Voice Assistant

Talk to Gemini Live from your microphone. Audio is sent to Google. Limited to 3 sessions per hour.

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Gemini AI Tools

Live Camera Assistant

Share a camera feed with Gemini Live. Frames and audio are sent to Google. Limited to 3 sessions per hour.

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Gemini AI Tools

AI Video Analyzer

Describe a short clip with Gemini. The video is sent to Google. Not a forensic review.

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Gemini AI Tools

AI Video Summarizer

Summarize an uploaded clip with Gemini. Cloud AI. Timestamps are approximate.

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Gemini AI Tools

Video Q&A

Upload a video once and ask Gemini questions. The file is sent to Google and reused this session.

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Gemini AI Tools

YouTube Video Analyzer

Analyze a public YouTube URL with Gemini. DevNestro does not download or rip the video.

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Gemini AI Tools

AI Video Generator

Generate a short video with Gemini Veo when a paid host is configured. Limited to 1 per hour.

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Gemini AI Tools

AI Video Editor

Describe a change to an uploaded clip. Editing is not assumed available. Fails closed on the free tier.

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Gemini AI Tools

AI Web Research

Ask a research question with Gemini Search grounding when a paid host is configured. Limited to 5 searches per hour.

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Gemini AI Tools

AI URL Analyzer

Analyze a public URL with Gemini URL context. DevNestro does not fetch the page. Private addresses are blocked.

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Gemini AI Tools

AI Local Research

Ask about places with Gemini Maps grounding when a paid host is configured. Limited to 5 searches per hour.

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Gemini AI Tools

AI Data Analyst

Paste a table or upload CSV for Gemini code-execution analysis. Data is sent to Google. Verify every number.

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Gemini AI Tools

AI Math & Calculation Assistant

Solve arithmetic, statistics, and formulas with Gemini. Not a loan, mortgage, APR, or gambling calculator.

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Gemini AI Tools

Semantic Text Similarity

Compare two texts with Gemini embeddings. A high score is not proof they mean the same thing.

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Gemini AI Tools

Semantic Search

Index a short list of texts with Gemini embeddings and rank a query. Vectors stay in memory for this session.

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Gemini AI Tools

Multimodal Similarity

Compare text or a supported document with Gemini embeddings. Image and media combinations fail closed on gemini-embedding-2.

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Gemini AI Tools

Function Calling Playground

Send a prompt and a JSON function schema to Gemini. DevNestro shows the requested function and does not execute it.

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Gemini AI Tools

Gemini Agent Playground

Combine Gemini built-in tools. Search is paid-only. No server command execution and no arbitrary MCP URLs.

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Gemini AI Tools

Remote MCP Playground

Remote MCP is disabled by default. Public users cannot point DevNestro at an MCP URL.

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Gemini AI Tools

AI Batch Processor

Submit multiple prompts to the Gemini Batch API on a paid host. Check status and download results. Free tier fails closed.

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Gemini AI Tools

Long-Context / Cache Demo

Create a temporary Gemini context cache from a large source, then ask multiple questions. Paid host only.

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Privacy & Trust

Safe-to-Share File Inspector

Inspect PDF, DOCX, images, and text in your browser for PII, secrets, metadata, links, QR, and provenance before you share.

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Business Tools

Invoice Generator

Create invoices with live preview, templates, and decimal-safe totals. Download PDF or print. Nothing is stored.

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Business Tools

Quote Generator

Create quotes and estimates with the same totals engine as invoices, without invoice-only payment wording.

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Security Tools

QR Safety Inspector

Decode QR codes locally, classify payloads, and review URL risk indicators. Links are never opened automatically.

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PDF Tools

PDF Watermark

Add a text or image watermark to a PDF in your browser. Presets for CONFIDENTIAL, DRAFT, COPY, and SAMPLE.

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PDF Tools

PDF Page Numbers

Add page numbers to a PDF in your browser with formats like Page 1 of N, custom prefix/suffix, and six positions.

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PDF Tools

PDF Protect / Password

Password-protect a PDF with real encryption. Briefly processed on the server, never stored, password not logged.

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PDF Tools

Compress PDF

Compress a PDF in your browser. Recommended, Maximum Compression, or Best Quality. Size stats appear after processing.

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Image Tools

Background Remover

Remove image backgrounds in your browser with a local AI model. Export transparent PNG. No paid API upload.

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Career Tools

Resume Builder

Build a resume with live preview, ATS-friendly templates, browser drafts, PDF export, and print. Not ATS guaranteed.

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Data Tools

CSV / Excel Chart Maker

Turn CSV or Excel into bar, line, pie, doughnut, area, or scatter charts in your browser. Export PNG, SVG, or PDF.

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Image Tools

Batch Image Toolkit

Resize, compress, convert, rename, rotate, and strip metadata for many images, then download a ZIP.

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PDF Tools

Secure PDF Redactor

Mark sensitive PDF regions, rebuild affected pages so underlying text is removed, verify extraction, then download.

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Design Tools

Social Media Safe-Area Simulator

Preview YouTube, Instagram, Facebook, LinkedIn, TikTok, and X crops with safe-area and UI overlays. Last verified dates included.

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Privacy & Trust

Before-Publish Media QA

Orchestrate metadata, GPS, PII, secrets, OCR, Content Credentials, and safe-area checks into a Critical / Recommendations / Passed report.

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Data Tools

Spreadsheet Formula Auditor

Audit XLSX formulas locally for pattern breaks, errors, external links, and hidden content. No auto-fix.

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Language & Writing Tools

Dictionary & Word Meaning Finder

Look up word meanings, parts of speech, phonetics, and examples from open dictionary data with clear attribution.

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Language & Writing Tools

Synonym & Antonym Finder

Find synonyms and antonyms, with optional AI-labeled tone groups for formal, casual, or intense wording.

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Language & Writing Tools

Grammar & Writing Helper

Check grammar and clarity with Gemini, then try tone rewrites. Your draft is sent to cloud AI when you run a check.

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Language & Writing Tools

Rhyme Finder

Find perfect and near rhymes from a local open word list. Useful for lyrics, poetry, and word play.

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Language & Writing Tools

Word Finder

Find words by starts-with, ends-with, contains, length, and wildcards. A word-game helper — not an official Scrabble or Wordle product.

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Language & Writing Tools

Example Sentence Generator

Generate example sentences for a word in different styles using Gemini. Outputs are labeled AI examples.

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Language & Writing Tools

Pronunciation Helper

Hear a word with browser speech, see IPA when available from open dictionary data, and get a syllable estimate.

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Language & Writing Tools

Vocabulary Quiz

Practice vocabulary with AI-generated multiple-choice quizzes by topic and difficulty.

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Language & Writing Tools

Word of the Day

A new English word each day for everyone, chosen deterministically from an open word list, with optional AI explanation.

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Language & Writing Tools

Slang Explainer

Explain slang and informal phrases with Gemini, including register warnings when a term may be offensive or dated.

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