Best YouTube Summarizer Extensions in 2026

YouTube summarizer Chrome extensions range from polished YouTube-only tools to broad browser assistants that also read PDFs and articles. The right pick depends on whether YouTube is your whole reading workflow or just one part of it, how often you hit free-tier limits, and whether you want to bring your own AI provider key instead of paying a subscription on top of the model.

Anya scans long competitor video essays for content research and needs takeaways without watching the full hour. Cleo turns lecture recordings into reusable study notes and is cost-sensitive — the "1 video per day" free tier most YouTube summarizers ship runs out fast. Nico wants to route the transcript directly to his own Anthropic or OpenAI key without an extension vendor in the middle.

This roundup compares the best YouTube summarizer extensions by transcript quality, timestamp navigation, multi-source coverage, BYOK support, free-tier honesty, and what happens to the summary after it's generated. Reduz appears in the list because Reduz is one of the products in the category — see the methodology box for what each tool was judged on.

Why use a YouTube summarizer Chrome extension?

A YouTube summarizer extension reads the transcript that's already on the watch page and turns it into bullets, key moments, and follow-up notes — without leaving YouTube. For Anya scanning a 90-minute panel discussion, that's a 90-minute decision compressed into 60 seconds of bullets. For Cleo turning a recorded lecture into study notes, it means the same workflow on every video instead of pasting transcripts into a chat tool. The extension category also fits videos that are paywalled or members-only — the source already exists in your tab. The right one supports the videos you actually watch (live streams, Shorts, age-gated content), gives you timestamps that jump the player back to source moments, and has a free tier that survives a real day of viewing.

The list

AI summarizer

Reduz

Reduz turns whatever you have open in Chrome into a clean summary: YouTube videos, PDFs, articles, webpages, and selected text. Use your own key from OpenAI, Anthropic, Google, DeepSeek, or xAI for unlimited use, with the key stored in Chrome on your device. Or start with 100 free credits a month, no card needed. Every summary saves to a searchable local history. Export to PDF, Markdown, or ZIP.

Best for:People who summarize YouTube videos, PDFs, articles, and webpages in Chrome and want to use their own AI key or start with free credits.

Fits Anya scanning competitor articles, Theo working through research papers, and Nico routing requests through a personal Anthropic key. Same extension, no account needed when you use your own AI key.

Strengths

Works on YouTube videos, PDFs, articles, webpages, and selected text from one extension.
Use your own AI key across OpenAI, Anthropic, Google, DeepSeek, or xAI. Keys stay on your device.
History, settings, and exports are local. Cloud backup is opt-in.

Tradeoffs

Focused on summaries. Not a chat assistant or browser automation tool.
AI generation still uses your selected provider in the cloud (local-first, not offline-only).

How to get started

Install Reduz from the Chrome Web Store.
Pick your own AI key or free credits in the first-run chooser.
Open the YouTube video, PDF, or article you want to summarize.
Click the Reduz toolbar icon.
Save, export, or copy the summary. Local history keeps it searchable.

Pricing:Free with 100 credits a month, no card. Using your own AI key is unlimited at provider rates (typically cents per article). Pro is $3/mo for 1,000 credits, Premium is $9/mo for 5,000 credits.

Read the Reduz comparison

YouTube-focused summary extension

Eightify

Eightify is a YouTube-only summarizer that injects a polished summary panel into the YouTube watch page with timestamps and translation across many languages. It runs on ChatGPT and Claude under the hood. The product is well-shaped for one job — watch a long video, get the takeaways — and not much else.

Best for:Users who mostly want fast YouTube takeaways directly inside the YouTube page.

Best when YouTube is the only summarization surface in the workflow. Less suitable for Theo with a PDF stack or Anya alternating between videos and articles.

Strengths

Focused product shape for YouTube video summaries.
Good fit when the job is scanning videos, podcasts, news, or tutorials quickly.
The narrow scope can feel simpler than a broad all-in-one assistant.

Tradeoffs

YouTube-only. PDFs, webpages, articles, and selected text are not in scope.
Free tier daily cap is small for heavier viewing days.
Renewal terms and cancellation flows are worth verifying before subscribing.

How to get started

Install Eightify from the Chrome Web Store.
Open a YouTube video.
Click the Eightify button in the YouTube panel or the toolbar icon.
Read the summary in the injected panel.
Sign in or start the trial to summarize beyond the free quota.

Pricing:Free tier with a small daily cap, plus monthly and annual paid plans. Check the current plan pricing on Eightify's site before subscribing.

Transcript and YouTube summary extension

Glasp YouTube Summary

Glasp's YouTube Summary extension is a popular YouTube summarizer. Its meaningful difference from the rest of the field is that the basic flow works with no sign-up required. Users pick which model processes the transcript (ChatGPT, Claude, Gemini, Mistral). The Glasp web app upsells highlighting, social-style learning, and a public profile around saved highlights, which is a separate decision from the extension itself.

Best for:Users who want quick YouTube transcript access, ChatGPT or Claude summaries, and optional Glasp reading workflows.

Good fit when YouTube is the main reading surface and creating one more account is the dealbreaker. Less suitable for Nico who wants direct from your browser-to-provider BYOK rather than Glasp's hosted relay.

Strengths

No-signup flow for basic YouTube summaries — rare in this category.
Strong YouTube transcript handling.
Multiple model choices (ChatGPT, Claude, Gemini, Mistral) without managing provider keys.

Tradeoffs

YouTube-centered. Multi-source workflows need a second tool.
The Glasp ecosystem is broader than private local summary history, so privacy expectations should be checked before opting into the web app.
Reviewers report transcript-extraction failures on specific videos.

How to get started

Install YouTube Summary with ChatGPT & Claude from the Chrome Web Store.
Open a YouTube video.
Click the Glasp icon in the description area or open the side panel.
Pick model and summary style in the extension settings.
Optionally sign up for the Glasp web app to highlight and revisit summaries.

Pricing:Free for the core YouTube summary path with no account. The Glasp web app upsells highlighting, notes, and a learning workflow on top.

All-in-one learning assistant

NoteGPT

NoteGPT is a broad learning-and-summary workspace: YouTube summaries, article summaries, PDF chat, audio transcription, mind maps, and study materials in one account. Free tier exists with daily caps — typically a small number of PDFs per day and a per-file size limit. Paid tiers raise the caps.

Best for:Students and creators who want summaries plus transcription, notes, writing, visual, audio, and study tools in one account-centered workspace.

Best for Cleo turning lectures and study materials into reusable notes. Useful when the workflow is reading, studying, and exporting study artifacts — not just summarizing one source.

Strengths

Broad source coverage across YouTube, PDFs, documents, audio, images, slides, and text.
Learning-oriented extras such as mind maps, chat-with-PDF, translation, and generated study materials.
Useful when a web workspace fits the workflow better than an extension alone.

Tradeoffs

The broad workspace can be heavier than a focused summarizer.
Local-first storage and BYOK provider control are not the primary product posture.
Hard free-tier daily caps push users toward the paid tier quickly.

How to get started

Sign up at notegpt.io or install the Chrome extension.
Open a YouTube video, paste an article URL, or upload a PDF.
Choose summary style or generate a mind map.
Export to Markdown, PDF, or download notes.
Upgrade to premium to remove daily caps.

Pricing:Free tier with daily caps and file-size limits, plus a paid premium plan. Check current plan details on the NoteGPT site.

All-in-one browser side panel

Sider

Sider is a multi-model side-panel AI assistant covering chat, summarization, writing, translation, and PDF analysis. It supports many AI models through a side-panel workflow — useful when summary is one job among several. Sider is paid-mostly: the free tier is small and the paid tiers gate model variety.

Best for:Users who want summarization, chat, writing, translation, PDF analysis, image tools, and multi-model access in one browser assistant.

Fits a user who wants chat, writing, and summarization in one panel and is comfortable with a subscription. Less suitable for Nico when local-first storage or BYOK is a hard requirement.

Strengths

Broad browser assistant with webpage and YouTube summarization.
Supports many AI models through a single side-panel workflow.
Covers reading, writing, translation, PDF analysis, and image workflows.

Tradeoffs

Broader than a focused summarizer, which can be more UI and account surface than needed.
Summary history and provider-key locality are not positioned the same way as Reduz Bring your own AI key.
Verify the pricing tier and renewal terms before subscribing.

How to get started

Install Sider from the Chrome Web Store.
Sign in or create a Sider account.
Open the side panel via the toolbar icon or shortcut.
Pick the model and command (summary, chat, translate, etc.).
Upgrade to a paid tier to unlock model variety and higher quotas.

Pricing:Tiered subscription model from a low monthly entry price up to higher-tier plans. Verify current credit limits and renewal terms on the Sider site before committing.

Automation-heavy browser assistant

HARPA AI

HARPA AI is a browser-agent assistant with 100+ predefined commands for summarization, web automation, monitoring, price tracking, and content workflows. It supports multi-model routing across GPT, Claude, Gemini, DeepSeek, and OpenRouter, and is notable for being one of the few mainstream extensions where bringing your own AI key is part of the offering — though on a paid tier rather than as the default.

Best for:Power users who want page-aware commands, web automation, monitoring, and summaries from one Chrome extension.

Fits Nico when the workflow extends past summaries into web automation and monitoring. Heavier than needed if the job is just reading a source and saving a clean summary.

Strengths

Strong automation posture with many predefined page-aware commands.
Supports webpage, YouTube, file, and PDF summarization workflows.
BYOK is genuinely supported, even if gated behind the lifetime tier.

Tradeoffs

More complex than a dedicated summarizer.
Automation depth can be unnecessary if the job is only reading, saving, and exporting summaries.
BYOK is on the paid tier, not the default mode.

How to get started

Install HARPA AI from the Chrome Web Store.
Sign in and choose a connection: CloudGPT, ChatGPT web session, OpenAI API, OpenRouter, or others.
Open a page and trigger a command like /summary or /youtube-summary.
Use the chat panel or quick-access bar to chain commands.
Add a personal API key on the X-tier plan if you want BYOK routing.

Pricing:Tiered monthly subscriptions plus a one-time X-tier lifetime plan that supports bringing your own provider key. A free tier exists with usage caps.

Other notable YouTube summarizer extensions

Smaller YouTube summarizers worth knowing about — useful if the main list doesn't fit a specific workflow.

Briefy
Summarizer with visual outputs — mind maps and tables — across YouTube, webpages, and PDFs. 4.6 Chrome rating. Useful when a video summary is one step before a structured artifact.
TubeOnAI
Cross-format summarizer covering YouTube plus PDFs, documents, audio, and video files. Smaller scale than Eightify or Glasp but broader source support.
Glarity
YouTube and Google-search summarizer using ChatGPT, Claude, or Gemini. Free with provider-side rate limits.
Recapio
YouTube-focused summarizer with chapter breakdowns. Smaller install scale, decent for quick takeaways.
NoteGPT YouTube Summary
NoteGPT publishes a YouTube-focused variant of its main extension. Same backend, lighter UI for users who only want video summaries.

YouTube-only can be enough — until it isn't

If YouTube is the entire job, a YouTube-specific extension like Eightify or Glasp YouTube Summary is simpler than a broader tool. The trade is that two months later, when you want to summarize the PDF the speaker referenced or the article cited in the description, you're back to a second tool. Reduz covers YouTube the same way and extends to PDFs, articles, webpages, transcripts, and selected text in one workflow with direct from your browser BYOK and local history. NoteGPT is right when study materials and mind maps matter more than provider control. Sider and HARPA are heavier than needed if summarization is the whole job. Pick the smallest tool that covers what you actually watch and read.

Frequently asked questions

What is the best free YouTube summarizer Chrome extension in 2026?

Glasp YouTube Summary works without sign-up and is one of the most-installed YouTube-only summarizers. Reduz's Hosted Free tier (100 monthly credits) does not require a credit card and covers YouTube plus PDFs, articles, and webpages. Eightify's free tier is technically free but the daily cap is small.

Can a YouTube summarizer extension work on videos without captions?

A reliable summary usually depends on usable transcript or caption data. If YouTube has not generated auto-captions and the creator has not uploaded subtitles, most summarizers — including Reduz — will fail to produce a useful summary. Some tools can fall back to audio transcription, but quality varies.

Do YouTube summarizer extensions work on YouTube Shorts and live streams?

Shorts work when the auto-caption system has processed the video — which is usually fast but not instant. Live streams are harder: the transcript is only partial during the broadcast. Most tools, including Reduz, work best on completed videos with finalized captions.

Can I use my own OpenAI or Claude API key for YouTube summaries?

BYOK for YouTube summaries is structurally rare. Reduz uses BYOK as a default mode (direct from your browser to OpenAI, Anthropic, Google Gemini, DeepSeek, or xAI). HARPA AI supports BYOK on its lifetime tier. Eightify, Glasp YouTube Summary, NoteGPT, Sider, and Monica all route through the vendor's own backend — you choose a model, but the request goes through their server first.

What's the most private way to summarize YouTube videos?

Reduz uses click-only permission for YouTube pages instead of permission to read every page, stores summary history in a your device on your device, and ships no analytics or telemetry. When you bring your own AI key the transcript goes directly from your browser to your selected provider with no Reduz server in the middle.

Why are people looking for Eightify alternatives?

Common reasons: the free tier daily cap is small for heavier viewing days, and the product is YouTube-only when many users also read PDFs and articles. See the Eightify alternatives roundup for direct replacements.

* Sources:Eightify, Glasp YouTube Summary, NoteGPT, Sider, HARPA AI.