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TubePrep

The Ultimate Zero-Upload
YouTube Creator Toolkit

Every file is processed 100% locally in your browser — no server, no upload, no tracking. Our client-side privacy moat means your content stays yours, always.

100% Private · No uploads · No tracking · No account

Thumbnail Safe Zone Previewer

Overlay YouTube UI elements on your 1280×720 thumbnail. Desktop & mobile views. Canvas API, no upload.

Smart Subtitle Cleaner

Strip timestamps & sequence numbers from .srt/.vtt files. Convert between formats and download locally.

Script Read-Time Estimator

Paste your script and instantly get estimated video length. Adjust for slow, normal, or fast speaking pace.

YouTube Chapter Validator

Validate & reformat messy timestamps into perfect YouTube chapters. Catches missing 00:00 and ordering errors.
Launch Creator Studio

The Only Free YouTube Creator Tools That Never Touch Your Files

TubePrep is a suite of free browser-based YouTube creator tools engineered around a single, unbreakable rule: your content never leaves your device. Every tool — from the YouTube thumbnail safe zone checker to the SRT timestamp remover — runs entirely inside your browser using the Web APIs built into Chrome, Firefox, and Safari. There are no servers, no file uploads, no tracking pixels, and no account walls. Just open the page and start working.

YouTube Thumbnail Safe Zone Checker & Previewer

Upload your 1280 × 720 thumbnail and our YouTube thumbnail previewer instantly overlays every UI element YouTube places on top of it — the title bar, the timestamp badge, the progress scrubber, and the channel avatar — across both desktop and mobile breakpoints. The YouTube thumbnail safe zone checker highlights the regions where your key text and faces are guaranteed to remain visible regardless of the viewer's device or playback context.

Why it matters

A thumbnail that looks perfect in Photoshop can have its headline clipped by the mobile timestamp badge — costing you clicks before the algorithm even surfaces your video. TubePrep renders the full safe-zone overlay in-browser using the Canvas API, meaning the image pixel data is decoded locally and discarded when you close the tab. Zero upload, zero risk.

Remove Timestamps from SRT Free — Clean SRT File Online

Auto-generated captions from YouTube Studio or Whisper are packed with sequence numbers, millisecond timestamps, and redundant blank lines that make them useless as scripts or blog posts. TubePrep's Subtitle Cleaner lets you remove timestamps from SRT free — paste or drop your .srt or .vtt file, choose what to strip, and download a clean SRT file online in seconds.

What you can strip

Because the entire parse runs in JavaScript inside your tab, your subtitle files are never transmitted to any server. This makes TubePrep the safest way to clean SRT files online, especially for confidential pre-release content.

Script Read-Time Calculator — Free Browser Teleprompter Aid

Before you hit record, know exactly how long your video will run. TubePrep's script read time calculator counts your words and projects your final video length across three speaking rates — slow (100 wpm), conversational (150 wpm), and fast (200 wpm) — so you can trim your script before you ever open a free browser teleprompter.

Ideal for

YouTube Shorts scripts that must stay under 60 seconds, long-form tutorials where you want to hit a 10-minute monetisation threshold, and podcast intros where pacing consistency matters. Your script text is processed entirely in-memory — no pasting to an external API, no log files, no data retention.

YouTube Chapter Formatter & Generator

YouTube chapters dramatically improve watch time and SEO by letting viewers jump to the sections they care about. But YouTube's chapter parser is unforgiving: chapters must start with 0:00, must be in ascending order, and require a minimum of three timestamps. TubePrep's YouTube chapter formatter and YouTube chapter generator validates every rule in real-time, flags errors inline, and auto-corrects common mistakes like missing leading zeros, out-of-order entries, and duplicate timestamps.

One-click copy-ready output

Paste your raw notes into the editor, fix any flagged issues with a single click, and copy the formatted chapter list straight into your YouTube description. The entire youtube chapter generator workflow happens locally — no API calls, no rate limits, no account required.

100% Client-Side — The Zero-Upload Privacy Advantage

Most online creator tools route your files through a cloud server. That means your unreleased thumbnails, confidential scripts, and caption files travel over the internet, touch someone else's disk, and enter retention policies you never agreed to read. TubePrep is architecturally different: every tool is implemented as a zero upload video tool — the computation runs entirely inside your browser tab using native Web APIs.

Start Using TubePrep's Free YouTube Creator Tools Now

Pick any tool from the dashboard above and you'll be up and running in under ten seconds — no install, no sign-up, no upload. TubePrep is free forever, built by creators who got tired of giving away their unreleased content to third-party servers just to check a safe zone or strip a timestamp. Your creative process deserves better.

Frequently Asked Questions

Everything you need to know about TubePrep

Quick answers to common questions about our tools — all of which run 100% in your browser with zero uploads.

Open TubePrep's Smart Subtitle Cleaner, paste or drop your .srt file, tick the 'Remove timestamps' option, and click Download. The entire process runs 100% in your browser using JavaScript — your file is never uploaded to any server, so your pre-release captions stay completely private.
YouTube's UI overlays — including the title bar, timestamp badge, progress scrubber, and channel avatar — eat into the edges of your 1280×720 thumbnail. TubePrep's Thumbnail Safe Zone Previewer renders every overlay live so you can confirm your key text and faces sit inside the safe region on both desktop and mobile, all processed client-side with no image upload.
YouTube requires chapters to start at 0:00, be in strictly ascending order, and include at least three entries with a minimum gap of 10 seconds between each. TubePrep's Chapter Validator checks every rule in real-time, flags inline errors, and auto-corrects common mistakes like a missing 00:00 or out-of-order timestamps — entirely in your browser, no upload needed.
At a conversational speaking pace of roughly 150 words per minute, a 5-minute YouTube video is approximately 750 words. TubePrep's Script Read-Time Estimator calculates your exact word count and projects video length across slow (100 wpm), normal (150 wpm), and fast (200 wpm) speaking rates — no server required, your script never leaves your device.
YouTube places the video duration badge in the bottom-right corner of your thumbnail, typically covering roughly 20% of the width on desktop and a larger proportion on mobile. TubePrep's Thumbnail Previewer overlays the exact badge position so you can make sure it doesn't obscure critical text — the overlay is drawn locally via the Canvas API, zero upload.
On mobile, YouTube uses a tighter aspect ratio crop and places the progress bar and title text lower on the thumbnail, which can slice off bottom content that looks fine on desktop. Use TubePrep's safe zone checker to preview both breakpoints side-by-side — everything runs client-side, so you can check unreleased thumbnails without worry.
TubePrep's Subtitle Cleaner strips all sequence numbers, timecode lines, and blank spacer rows from your .srt or .vtt file in one click, leaving clean, readable plain text ready to repurpose as a blog post or show notes. The conversion is handled entirely in your browser with no upload, so sensitive pre-release transcripts never leave your machine.
Yes — TubePrep's Subtitle Cleaner uses the browser's File API to read your .srt file locally and strips timestamps purely in JavaScript, so the file data is never serialised over the network or stored on a server. You get a downloadable plain-text file in seconds, with zero upload and zero data retention.
Each YouTube chapter must be at least 10 seconds long, and videos must include a minimum of three chapters for the chapter navigation panel to appear. TubePrep's Chapter Validator enforces both rules automatically, highlighting any chapters that are too short so you can fix them before publishing — all checked locally, no upload.
Absolutely. TubePrep's Thumbnail Safe Zone Previewer decodes your image entirely within your browser using the Canvas API — the pixel data never leaves your device and is discarded the moment you close the tab. There is no server, no cloud storage, and no account, making it the safest way to verify unreleased or confidential thumbnails online.
YouTube recommends a resolution of 1280×720 pixels (16:9 aspect ratio), with a minimum width of 640 pixels, and a maximum file size of 2 MB in JPG, PNG, GIF, or WebP format. TubePrep's Thumbnail Previewer is optimised for 1280×720 canvases, rendering the full safe-zone and UI-overlay preview client-side — no upload, instant results.

Still have questions? Explore the tools →