初期設定で非公開
保存した音声は公開プレイリストではなくフィードになります。
すべての非公開 RSS URL はフィードトークンを使うため、聴取ルートは Square の公開共有と分離されます。
あとで聴くインボックス
保存した音声のための非公開ポッドキャストインボックス。
Castline turns uploaded audio files, direct audio URLs, text, and articles into token-protected podcast feeds you can open in any podcast app.
Save Drop audio links, files, text, or articles into one inbox
Feed Keep delivery private with token-protected RSS
Play Listen from the podcast app you already use
ひとつの聴取習慣
ファイル、URL、記事、テキストは同じポッドキャストワークフローに入ります。
Free users get a focused inbox. Pro raises the ceiling for daily research, reading, and listen-later routines.
流れ
- 01ソースを追加音声をアップロードするか、直接 URL、テキストメモ、記事を保存します。
- 02エピソード生成Castline が音声を保存し、非公開 RSS フィードを更新します。
- 03どこでも聴くOpen the feed in Apple Podcasts, Overcast, Pocket Casts, or another podcast app.
Square
Public audio shared from Castline.
Listen first, then open the public page or share the link.
Saved
Public feeds you follow.
Saved feeds are shortcuts to public listening pages. They do not copy episodes into your private inbox.
Price
Early Pro pricing for people building a real listening habit.
Free is for a small listen-later inbox. Pro is intentionally priced like a lightweight utility, not another heavy SaaS bill. The current checkout is monthly while Castline is early; a lifetime-style option is part of the pricing roadmap.
Small bill, useful ceiling.
$2.99/month keeps the upgrade decision low-friction while raising the limits enough for daily saved-audio, article-to-podcast, and research listening workflows.
Early supporters should keep upside.
The plan is to keep early Pro users close to future improvements: cleaner article extraction, better feed organization, saved public feeds, and more podcast-app polish.
One-time access is on the table.
Castline is not selling lifetime access yet, but the pricing direction is to offer a lifetime-style purchase once usage costs and TTS economics are stable enough.
Free
$0/month
Start with one private あとで聴くインボックス.
- Private feeds
- 1 default inbox feed
- Audio episodes
- 5 episodes
- Managed storage
- 500 MB
- Monthly transfer
- 2 GB
- Audio URL imports
- 5 per month
- Text and article TTS
- Not included
- Public sharing
- Share up to 3 single episodes
Pro
$2.99/month
For heavier saved-audio and article listening workflows.
- Private feeds
- 20 feeds
- Audio episodes
- 200 episodes
- Managed storage
- 20 GB
- Monthly transfer
- 100 GB
- Audio URL imports
- 100 per month
- Text and article TTS
- 200,000 characters per month
- Public sharing
- Share episodes and publish full public feeds
What Pro is meant to grow into
Pro should feel like the private audio layer for everything you want to hear later: saved files, direct audio URLs, long articles, work briefings, public feed follows, and eventually cleaner automations around the podcast apps you already use.
- Better article audioCleaner extraction, more reliable text cleanup, and voice controls that fit long-form listening.
- Stronger feed workflowsMore ways to organize inbox feeds, publish selected feeds, and keep private RSS access separate from public sharing.
- Pricing flexibilityA lifetime-style option is a target once recurring media and generation costs are predictable.
Settings
Workspace settings
Podcast Defaults
New feed behavior
Defaults used when new feeds and episodes are created.
Privacy & RSS
Private feed access
Private feed access and podcast app delivery controls.
RSS token
Rotation immediately invalidates old RSS and media URLs.
Storage
Managed audio
Managed audio limits and retention preferences.
Upload limit
Maximum size per audio item.
100 MB
Local cache
Clear browser-stored feed previews.
Account
Workspace identity
Profile, identity, and default workspace routing.
Session
Authentication powers private feed ownership.
Optional
RSS owner path
Used in project-scoped private feed URLs.
/u/local
Account menu
Sign in, account controls, and sign out.
Plan and usage
Current plan limits and monthly resource usage.
Upgrade workspace
Unlock more feeds, higher audio limits, and TTS when it is available.
Workflow
Audio collections, delivered as private podcasts.
-
01
Save
Quick-add audio to the default あとで聴くインボックス.
-
02
Store
Castline keeps uploaded files and direct audio URLs in managed storage.
-
03
Listen
Open the private inbox feed in your podcast app.
Use cases
A personal podcast feed for repeat listening workflows.
Save finished audio for later
Castline is for people who already have audio files or direct audio URLs and want those items delivered through a private podcast feed instead of scattered downloads.
Explore listen-later audio inbox workflows個人用ポッドキャストフィードを作成
Each personal podcast feed uses private RSS and protected media URLs, so saved audio and generated episodes can be opened in podcast apps without publishing a public show or directory listing.
個人用ポッドキャストフィードを見るOrganize research and work audio
Founders, researchers, operators, and creators can collect calls, briefings, interviews, or downloaded audio into one listen-later inbox that follows them into their podcast app.
Explore private podcast feed delivery記事をポッドキャストエピソードに変換
Pro users can turn pasted text and article URLs into generated audio episodes, then listen later from the same personal podcast feed they use for saved audio.
Explore article to podcast workflowsConvert audio URLs into podcast RSS
Direct audio URL imports let Castline store podcast-ready audio and deliver it through private RSS instead of leaving audio links scattered across tabs, chats, and documents.
Explore audio URL to podcast RSSFAQ
Common questions about Castline
What is Castline?
Castline is a web app for saving audio files, direct audio URLs, text, and articles into a private personal podcast feed with RSS delivery.
Can I create a personal podcast feed with Castline?
Yes. Castline creates personal podcast feeds for saved audio and readable content, with private RSS delivery that can be opened in standard podcast apps.
Does Castline create public podcasts?
Castline focuses on private podcast feeds protected by feed tokens, so saved audio can be opened in podcast apps without publishing a public show.
What audio sources does Castline support?
Castline supports audio file uploads and direct audio file URLs such as MP3, M4A, AAC, WAV, OGG, and WebM. Pro users can also generate podcast-ready audio from pasted text and article URLs.
How does Castline protect private podcast feeds?
Castline protects each private RSS feed and its media URLs with feed tokens. Rotating a token invalidates old RSS and protected media URLs, which helps keep saved audio private.
How much does Castline cost?
Castline has a Free plan for one default inbox feed and a Pro plan at $2.99 per month for more feeds, more episodes, higher storage, and higher monthly transfer limits.
Is Castline a YouTube downloader?
No. Castline supports uploaded audio files and direct audio file URLs. It is not a YouTube downloader, video converter, public podcast host, or automatic channel sync tool.