Podcast hosting is, under the hood, file storage plus an XML feed — and Transistor charges $19–99/month for it, forever. Castport runs the whole thing on your own $5 VPS or desktop: upload an episode, get an Apple/Spotify-valid RSS feed, clean public pages, an embeddable player and privacy-safe download stats. $39 once, and your audio files are never held hostage.
If you've searched for a Transistor alternative, Castport is the pay-once option worth putting at the top of the list: Castport is $39, one time, and covers the same core job Transistor charges $19/mo for.
What makes Castport the pick for 2026
- Unlimited shows & episodes — Each show gets its own artwork, iTunes category, language, explicit flag and custom feed slug. No per-show pricing tiers.
- Apple/Spotify-valid RSS — RSS 2.0 with the full itunes namespace, exact enclosure byte lengths, permanent GUIDs and valid pubDates — the details that actually get feeds rejected, done right.
- Streaming uploads — MP3 or M4A streamed straight to disk — no buffering 200 MB files in memory — with markdown show notes, episode/season numbers and per-episode artwork.
- Podcasting 2.0 chapters — A chapters editor (start time + title) that also emits the podcast:chapters JSON endpoint modern apps read.
- Scheduling — Set a future publish date and the episode stays hidden from the feed and public pages until then — no cron job needed.
Castport vs Transistor, at a glance
| Castport | Transistor | |
|---|---|---|
| Price | $39 once | $19–99/mo, forever |
| Cost over 3 years | $39 | $684–3,564 |
| Shows | Unlimited | 1 to unlimited depending on tier |
| Downloads | Unlimited | Metered on lower tiers |
| Your own domain | Yes, natively | Paid plan only |
| Audio files | Always yours, on your disk | Hosted on their infra |
| Podcasting 2.0 chapters | Built in | Limited |
| Source code | MIT, on GitHub | Closed |
Pays for itself in 2.1 months against Transistor Starter — or under a month against Growth. Over 3 years you keep $645–3,525.
Common questions
Is it really free on GitHub?
Yes — MIT source at github.com/bensblueprints/castport-mvp, always. $39 buys the packaged installer, guided deploy and lifetime updates.
Will Apple and Spotify actually accept the feed?
That's the part we sweated: exact enclosure byte counts (not estimates), permanent GUIDs, real probed audio durations, and proper HTTP Range support on audio — the exact details that get naive feeds rejected. Set BASE_URL to your real domain first; localhost feeds are rejected.
Who pays for the bandwidth?
You do — that's the honest trade-off of self-hosting. A $5 VPS comfortably serves a typical indie show; a genuinely huge audience is where Transistor's managed CDN infrastructure earns its monthly fee.
The bottom line
Castport won't out-feature Transistor on every axis — no subscription tool with a bigger team and a bigger roadmap loses on everything. But for the core job, $39 once against $19/mo forever is a trade most people should at least look at. Castport is part of OneTimeSuite, a catalog of pay-once apps that replace subscription SaaS.
Try Castport — $39, once
Upload episodes, get a valid RSS feed, public pages, embeddable player & download stats. Pay once.