Sinch is a serious piece of infrastructure. It runs global SMS, voice, email, WhatsApp, RCS, and a verification/2FA stack, and a lot of very large companies route a lot of traffic through it. If you're an engineering org standardizing on one omnichannel API across forty countries, Sinch is a reasonable place to be.
But a lot of people who go looking for "a Sinch alternative" don't actually need a global omnichannel CPaaS. They need to send SMS in the US (maybe Canada), get replies in an inbox, stay compliant with 10DLC, and not hire a developer to glue it all together. That's a different product. This post is about that gap.
Full disclosure: I work for ReadySMS, so I have a side here. I'll try to be honest about where Sinch is genuinely the better choice — because for some readers it is.
Where Sinch is genuinely strong
I'm not going to pretend Sinch is weak. For its category it's one of the strongest options out there. Confirm specifics at their site, but the things that make Sinch the right call are real:
- True omnichannel under one roof. SMS, MMS, voice, email, WhatsApp, RCS, plus verification/2FA. If your product needs three or four of those channels through one vendor relationship, that consolidation has real value.
- Global reach. Direct carrier connections across a huge number of countries. If you're sending to subscribers in Brazil, India, and Germany the same week, this matters a lot.
- Enterprise-grade scale and SLAs. Built for very high throughput, with the support and contracts a large enterprise expects.
- A deep, well-documented API. It's a developer platform first. That's a strength if you have developers.
That last point is also the catch. Sinch is a CPaaS — a communications platform as a service. The platform part is an API. To turn it into something your marketing team or your sales reps can actually use, somebody builds the application layer: the campaign sender, the inbox, the opt-out logic, the scheduling, the dashboards. That somebody is you.
The hidden cost of "raw CPaaS"
The per-message price on a raw CPaaS is only one line of the budget. The bigger number is usually the build.
Think about what a usable SMS operation needs that a raw API doesn't hand you:
- A conversations inbox so replies don't vanish into a webhook
- Bulk campaign scheduling and contact lists
- STOP/UNSUBSCRIBE handling that suppresses the opt-out across every future send
- Quiet-hours logic per recipient time zone
- 10DLC brand and campaign registration wired into the send path
- Templates, reporting, and someone to maintain all of it
On a CPaaS, that's a development project — and then it's a maintenance project forever. For a team whose core business isn't building messaging software, that's a strange thing to own. We wrote more about skipping the carrier-API build in the Bandwidth alternative post and the Plivo alternative post; the logic is the same for Sinch.
What ReadySMS does differently
ReadySMS sits as a thin, transparent layer over carrier infrastructure. We're not trying to be omnichannel-everything across the planet. We're trying to make registered US/Canada SMS (plus outbound voice) cheap, compliant, and usable without code. The tradeoff is deliberate: less breadth, far less setup.
Here's the honest side-by-side.
| Sinch | ReadySMS | |
|---|---|---|
| Category | Global omnichannel CPaaS (API-first) | No-code SMS + voice platform |
| Channels | SMS, MMS, voice, email, WhatsApp, RCS, 2FA | SMS/MMS + built-in power dialer |
| Geographic focus | Global, many countries | US / Canada |
| Built-in inbox & campaigns | You build it on the API | Included |
| 10DLC registration | Your responsibility to wire up | Done in-app |
| Power dialer | Separate voice product/build | Included add-on |
| GoHighLevel integration | DIY via API | Native OAuth, two-way |
| Free to try | Check their site | 20 free test sends + $25 credit at registration |
The point of the table isn't "ReadySMS wins every row." Sinch wins the channels row and the geography row outright. The point is matching the tool to the job. If your job is SMS in North America, the rows that matter all land on the simpler side.
Cheap registered SMS
ReadySMS pricing is per outbound segment plus a flat $0.0045/segment carrier pass-through that we itemize separately instead of baking into a single number. Tiers run from $0.0155/segment on Starter (0–50,000/mo) to $0.0125 on Growth (50k–500k) and as low as $0.0028 at Enterprise (500k+/mo volume).
Worked example. Say you send 100,000 segments a month — that lands in the Growth tier at $0.0125:
`` 100,000 × ($0.0125 + $0.0045) = 100,000 × $0.0170 = $1,700/month ``
Watch your unicode, though. Drop an emoji into a 175-character promo and you've turned a 70-char-per-segment unicode message into 3 segments. That same 100,000-contact blast becomes 300,000 segments — $5,100 instead of $1,700. The carrier doesn't care that it's "one message"; it bills per segment. We break the pass-through line down further in this post on the $0.0045 line item.
I won't quote Sinch's per-message price — confirm it at their site. The honest framing is that the underlying carrier cost is similar across providers; what differs is the markup and what you have to build to use it.
Done-for-you 10DLC
US A2P 10DLC is mandatory, and unregistered traffic gets carrier-filtered into oblivion. On a raw CPaaS you handle brand and campaign registration yourself through their tooling. ReadySMS does it in-app: brand + campaign registration, roughly ~$10/mo per brand and ~$20/mo per campaign in carrier fees, approval typically in 4–7 business days.
It's not just paperwork. The compliance stack runs on the send path: automatic STOP/opt-out propagation across campaigns, quiet-hours enforcement by recipient area, and optional litigator/DNC scrubbing before send. If you want the deeper version, the 10DLC explainer and what actually gets approved are both worth a read before you register.
A note on framing, because honesty is the brand: none of this makes you lawsuit-proof. Compliance is ultimately the sender's responsibility. These features reduce exposure and document consent; they don't eliminate risk.
Native GoHighLevel integration
If you live in GoHighLevel, this is the deciding factor. ReadySMS connects to GHL via OAuth with two-way sync of inbound and outbound messages, mapped per location / sub-account so agencies keep clients isolated. On Sinch you'd be writing and maintaining that integration yourself. There's no native GHL connector waiting for you in a raw CPaaS.
If GHL is your stack, start with the GHL SMS setup guide and the best SMS provider for GoHighLevel guide.
A built-in power dialer
Sinch has voice as an API. ReadySMS has a power dialer as a usable product — manual and queue dial, call recording, voicemail drop, transfer/barge/whisper, and speed-to-lead auto-dial on new leads. Plans start at a Free tier ($0/mo, 1 agent, 500 minutes included, then $0.06/min), through Pro at $29/agent/mo ($0.05/min) and Team at $69/agent/mo ($0.0375/min).
The combination is the useful part: a new lead comes in, ReadySMS fires an instant text and auto-dials a rep inside the first few minutes. Building that orchestration on a raw CPaaS is a project. Here it's a toggle. Pricing for both lives on the pricing page.
When you should actually stay on Sinch
I'd be doing you a disservice if I pretended ReadySMS fits everyone. Stay on Sinch (or pick it new) if:
- You genuinely need multi-channel — WhatsApp, RCS, email, and SMS through one vendor.
- You're sending internationally at meaningful volume across many countries.
- You have developers who want an API to build on, and a real application to build it into.
- You need enterprise contracts, custom SLAs, and a named account team.
In those cases the build cost is justified because you're building something specific, and the breadth is the whole point. A no-code North American SMS platform would just get in your way.
The decision in one paragraph
If you're an engineering-led org running global omnichannel messaging, Sinch is built for you and ReadySMS isn't trying to replace it. If you're a US/Canada sender who mostly does SMS, wants replies in an inbox, needs 10DLC handled, and would rather not staff a messaging-software project — that's the gap ReadySMS fills, at a couple of cents per segment with the carrier fee shown separately.
A low-commitment next step
You don't have to decide on a spreadsheet alone. Run your real volume through the cost calculator, then take the 20 free test sends (plus a $25 credit when you submit 10DLC registration) and send a small registered campaign to feel the difference between an API you build on and a platform you log into. If it's not the right fit, you'll know fast — and you'll have lost nothing but an afternoon.