SendBird vs Firebase 2026: Prices, Alternatives & Custom

Updated October 2026: current list prices for Sendbird, Stream, PubNub, Ably, CometChat, Agora Chat and Firestore; a SendBird alternatives table; a worked Firestore cost example at 1M MAU; Perspective API’s 31 December 2026 shutdown.

Why Fora Soft wrote this guide

Fora Soft has been shipping communication products with embedded chat since the WebRTC era began. Recent examples: Sprii (live video shopping with high-burst chat), TransLinguist (interpretation chat alongside video), BrainCert (classroom chat at scale), MyOnCallDoc (HIPAA-grade clinical messaging), Nucleus (on-premise messaging for regulated industries) and Speakk (anonymous voice + chat).

We’ve shipped on Firebase, on SendBird, on Stream, on raw Socket.io, on Centrifugo. We have no SaaS partnership to defend in this comparison. The recommendations below reflect what we’d pick for our own founders if we were starting again today.

SendBird vs Firebase: the short answer

SendBird is a finished chat product; Firebase is a realtime database you build chat on. Pick SendBird when you want threads, moderation, push and compliance paperwork in a week or two and can pay per monthly active user: its public Chat plans start at $349–$599 a month for 5,000 MAU (Sendbird pricing page, October 2026). Pick Firebase when your own mobile engineers will build presence, moderation and search, and you would rather pay per read and write: Cloud Firestore charges $0.03 per 100,000 reads and $0.09 per 100,000 writes after a free 50,000 reads and 20,000 writes a day (Google Cloud, October 2026).

If chat is the product, regulation is heavy, or your 18-month plan goes past roughly 500k MAU, model a third option too: a custom Node.js + Socket.io backend. The table is the one-glance version; the sections below explain each call.

Five shifts reshaping chat backends in 2026

1. End-to-end encryption is now table stakes for regulated tiers. Healthcare, finance, legal and government RFPs assume E2EE as an option. SaaS vendors that don’t support it lose deals.

2. AI moderation matured fast. Production-grade automated moderation for spam, abuse and PII lifts the floor on what custom builds need to ship; CSAM still needs hash matching such as PhotoDNA on top. SaaS vendors all bundle moderation; custom builds plug in a model such as the OpenAI moderation endpoint. Google’s Perspective API, a common choice until now, is being shut down on 31 December 2026, so new builds should not depend on it.

3. Video + chat is the default surface. Standalone chat products are commoditised; chat embedded inside a video, live-shopping or telemedicine flow is the new battleground.

4. MAU pricing is under pressure. Buyers compare SendBird-style MAU bills against fully-loaded custom-build costs and increasingly find the second cheaper above 500k MAU. Vendors are responding with negotiated caps and per-feature pricing.

5. Data residency stopped being optional. Russia (Federal Law 152-FZ) requires citizens’ personal data to be stored in-country, Saudi Arabia’s PDPL restricts transfers abroad, and EU buyers increasingly write EU-only storage into contracts. Federated stacks (Matrix) and self-hostable open source are getting fresh attention.

The three paths — SaaS SDK, managed realtime, custom build

Most chat-backend conversations end up in one of three buckets. Pick the path first; the vendor afterwards.

Path A — SaaS chat SDK

SendBird, Stream Chat, Twilio Conversations, Ably. Drop in an SDK, get the standard feature set in a week or two, run on the vendor’s infrastructure. Pricing is MAU-based with feature add-ons. Best when chat is a feature, not the product, and total chat MAU stays under ~500k for a while.

Path B — managed realtime database

Firebase Realtime Database / Firestore, Supabase Realtime, Ably channels. You build the chat UX yourself but lean on a managed realtime backend for sync. Cheaper at small scale, more flexible than a chat SDK, no MAU ceiling on the realtime layer itself, but you own the moderation, history, search, and push integrations.

Path C — custom build

Node.js + Socket.io, Go + Centrifugo, Phoenix Channels (Elixir), or a Matrix federation. Postgres or Cassandra for storage; Redis for presence; Kafka or NATS for fan-out; FCM/APNs for push. Most operational burden, most flexibility, lowest unit cost above ~500k MAU. The path Fora Soft picks when chat is core to the product, and the base our video chat app development team adds calls and screen share on top of.

Figure 1. Firebase, SendBird and a custom Node.js + Socket.io build compared across the seven trade-offs that decide the pick.

Comparison matrix — the three protagonists head-to-head

Indicative numbers below assume a B2B/B2C chat with mainstream features (DM + group, attachments, push, search, moderation). List prices were checked in October 2026; tiers and discounts move, so verify before procurement.

Figure 2. Directional monthly cost by MAU: a custom build’s fixed team and infra undercut MAU-priced SaaS somewhere around 500k MAU.

Firebase — the cheapest path until it isn’t

Firebase Realtime Database and Firestore give you instant data sync, offline support, and integrated push (FCM) on a generous free tier. Auth, storage, and security rules round out the package. For a mobile-first app with <300k MAU, you can ship a working chat in five days and pay almost nothing.

Strengths. Mobile SDK quality is excellent. Offline sync “just works.” FCM is the canonical push channel. Security rules are good enough for most cases.

Weaknesses. No native chat features: you build presence, history, search, moderation, threads, reactions. Every message delivered to every listener is a billed document read, so large groups and listeners on whole collections multiply the bill. E2EE isn’t bundled. Data residency control is coarse. HIPAA-eligible only with the right configuration and BAA paperwork.

Firestore cost, worked example. Take 1M MAU, 30% of them active each day, each active user sending 20 messages into five-person chats and loading 100 history messages. That is about 6M writes and 60M reads a day, or 180M writes and 1.8B reads a month: roughly $160 plus $540 at Firestore’s October 2026 list prices. The database line itself stays small. What grows the bill is fan-out to big groups, listeners that re-read whole collections, Cloud Functions for push and moderation, and network egress. Model your own read pattern before you trust anyone’s “Firebase gets expensive at X” rule, ours included.

SendBird — the fastest path to a polished chat

SendBird ships everything: 1:1 and group chat, threads, reactions, presence, typing, read receipts, push, moderation, AI moderation, message search, attachments, voice and video calls, broadcast channels. Mature SDKs across iOS, Android, web, React Native, Flutter, Unity. SOC 2, GDPR, HIPAA available.

SendBird pricing in 2026. The public Chat plans start at the 5,000-MAU tier: Starter costs $349 a month billed annually ($399 monthly) and Pro $499 ($599 monthly), with peak concurrent connections capped at 5% of the MAU limit. Anything bigger is an Enterprise quote (Sendbird Chat pricing, checked October 2026). There is a free trial up to 1,000 MAU and a free Developer plan for building. Since February 2025 Sendbird also sells an AI agent for customer service, so expect part of the sales conversation to be about its AI products.

Strengths. Production-grade out of the box. Time-to-MVP measured in days. SLAs and enterprise support. Compliance documentation off the shelf.

Weaknesses. MAU-based pricing escalates above ~500k MAU. Customisation hits a ceiling on UX, moderation rules, and data shape. Lock-in is real — migrating off SendBird is a multi-quarter project. E2EE only on the premium tier and with constraints.

Custom Node.js + Socket.io — when chat is the product

Socket.io on Node.js (or Centrifugo / nchan / Go WebSockets, Phoenix Channels in Elixir) lets you own every layer. The realistic stack: WebSocket gateway behind a load balancer; Redis for pub/sub and presence; Postgres for history; S3 (or KMS-encrypted equivalent) for attachments; Kafka or NATS for fan-out at scale; FCM and APNs for push.

Strengths. Total control of features, data shape, latency budget, encryption model, moderation rules, and unit economics. Cleanest fit when chat is tightly coupled to other product surfaces — live shopping carts, video co-watch, regulated workflows.

Weaknesses. The team owns scaling, on-call, abuse, search relevance, and every edge case the SaaS vendors handle for you. Underestimating the operational tail is the single biggest mistake we see.

Figure 3. The realistic stack for a custom chat backend: a Socket.io gateway fanning out to Redis, Postgres, object storage, moderation and push.

A 6-week MVP shape for a custom chat build

Week 1–2  WebSocket gateway (Socket.io / Centrifugo) + auth + JWT
Week 2–3  Postgres message store + sequence numbers + history API
Week 3–4  Redis presence + typing indicators + read receipts
Week 4     Push (FCM / APNs) for offline delivery
Week 5     Attachments (S3 + virus scan) + image/video previews
Week 5–6  Moderation (regex + OpenAI moderation API or a self-hosted classifier)
Week 6     Search (Postgres tsvector or OpenSearch) + retention policies
Week 6     Observability + load test + chaos drill

Scaling math — what to expect from each layer

For planning, assume a single Node.js Socket.io process holds about 5,000 active connections, and 10k or more with tuning; memory and message fan-out set the real limit, so load test your own traffic. Go-based gateways (Centrifugo, custom WebSocket servers) hit 30k–50k per node. Multi-node Socket.io needs both sticky sessions and a Redis (or similar) adapter, so plan them from day one.

Push is usually the cheapest layer (FCM and APNs are free); messaging storage and search dominate cost above 500k MAU. Run the unit-economics model before you commit; our hosting comparison covers cloud-vs-bare-metal trade-offs.

SendBird alternatives in 2026: prices and best fit

The strongest SendBird alternatives in 2026 are Stream Chat (the closest feature match), PubNub and Ably (realtime infrastructure you build chat on), CometChat and Agora Chat (lower entry prices), Twilio Conversations (if you already use Twilio for SMS or voice), Firebase or Supabase Realtime (chat on top of your database) and Matrix (self-hosted, federated, end-to-end encrypted). List prices below were taken from each vendor’s pricing page in October 2026.

SendBird vs Stream. Stream Chat (getstream.io) has a comparable feature set and strong React and React Native SDKs. At list price Stream’s Start plan includes 10,000 MAU for $399 a month billed annually, where Sendbird’s entry tier includes 5,000 MAU for $349, so Stream is usually cheaper per MAU before negotiation (October 2026). Choose by SDK fit and moderation tooling, then negotiate both.

SendBird vs PubNub. PubNub sells realtime messaging infrastructure billed by MAU or transactions, with chat features you assemble on top. It is cheaper to start ($98 a month for 1,000 MAU) and flexible, but SendBird gives you more finished chat out of the box: UI kits, moderation dashboards and threads.

Migrating from Firebase or a self-hosted Socket.io server. Moving to a managed chat service is mostly a data-mapping job: users, channels, message history, attachments and push tokens. Stream documents a bulk import for users, channels and messages; with any vendor, plan 4–8 weeks of engineering plus a parallel run, and rewrite attachment URLs before cutover.

Twilio Conversations. Pairs well if you’re already on Twilio for SMS or voice; one thread across SMS, WhatsApp and chat is the differentiator. Twilio’s docs now call it Conversations (classic), next to a new Conversations API for its orchestration products, so confirm the roadmap with your account team. Our Twilio development and migration team builds on Conversations and moves teams off it when the bill outgrows the product.

Ably. Realtime channels with strong delivery guarantees; sits between Firebase Realtime DB and SendBird in scope. Great for multi-tenant chat where you build the chat layer yourself.

Supabase Realtime. Postgres + WebSockets with row-level security. Strong choice if your data already lives in Postgres and you want chat as a feature, not a separate stack.

Matrix protocol (Element / Synapse / Dendrite). Federated, open-source, self-hostable; E2EE is on by default for private rooms and DMs, which limits server-side search and moderation. The right answer when sovereignty and federation matter (defence, public sector, multinationals).

XMPP servers (ejabberd, MongooseIM). Old, battle-tested, still in production at telcos. Reach for them when you need millions of concurrent users on commodity hardware and the team can run them.

The twelve chat features that actually matter in 2026

If your chat ships only these twelve and gets each one right, you’ve covered 95% of real demand.

Compliance, in plain language

GDPR. A lawful transfer mechanism for personal data leaving the EEA (GDPR does not mandate residency, but EU contracts often do); data subject access and deletion within one month (Article 12(3)); lawful basis (Article 6); DPA with every processor; breach notification within 72 hours. All three paths can comply with the right configuration.

HIPAA. AES-256 at rest, TLS 1.2+ in transit, RBAC, audit logs, BAAs with every sub-processor, six-year retention of compliance documentation (45 CFR 164.316). SendBird and Twilio offer HIPAA tiers; Firebase requires careful configuration on a HIPAA-eligible Google Cloud footprint; custom builds put you in full control. More on the NFR side here.

SOC 2 Type II. Increasingly demanded by enterprise buyers. SaaS vendors usually have it; on a custom build budget for a 12-month roadmap to your own SOC 2.

E2EE. Optional for B2C, contractual for healthcare and legal. Signal Protocol on a custom build, vendor premium tier on SaaS, third-party libraries on Firebase.

A five-question decision framework

Q1. Is chat your differentiator or a feature? Differentiator → custom. Feature → SaaS or Firebase.

Q2. What’s your realistic 18-month MAU? <100k → Firebase or SaaS. 100k–500k → SaaS sweet spot. >500k → model the custom-build economics.

Q3. What regulation applies? HIPAA / strict residency / E2EE-mandatory → custom or SendBird/Twilio premium. Standard B2B SaaS → any path.

Q4. How tightly is chat coupled to other product surfaces? Loose (Slack-style standalone) → SaaS. Tight (live shopping, telemedicine, in-game) → custom.

Q5. Can you afford the operational tail? If your team can’t carry on-call, search relevance, abuse moderation and push reliability, take the SaaS hit and ship, or bring in a dedicated development team that owns the realtime backend and its on-call.

Figure 4. A five-question path from chat requirements to Firebase, a SaaS SDK, or a custom build.

Five pitfalls that wreck chat backends

1. Underestimating WebSocket scale. Latency is fine at 5k connections per node, painful at 30k. Plan multi-node from day one and load test honestly.

2. Sloppy message ordering. Distributed systems lose “happens-before.” Use sequence numbers per channel, not server timestamps.

3. Push delivery as an afterthought. FCM and APNs both refuse delivery for many reasons. Real push success is 80–90%, not 99%. Build for it.

4. Ignoring moderation until launch. Manual moderation queues drown teams of 50,000+ MAU. Layer regex + automated moderation + human review from week one.

5. SaaS MAU explosion. A free user is still an MAU. Inactive cohorts cost the same as active ones. Negotiate caps or build retention before scaling marketing.

KPIs that prove your chat is healthy

Reliability KPIs. Connection success rate (target >99%), message delivery latency p95 (target <300 ms), durability (zero-message-loss policy), push delivery success (target >90%).

Quality KPIs. Moderation false-positive rate (target <1%), false-negative rate (target <0.1%), search relevance (manual sample), attachment scan success.

Business KPIs. Cost per active user, cost per delivered message, gross margin per MAU, retention of chat-active users at 30 days, share of users who send a second message in week one (the activation gate that predicts retention).

Mini case — from SendBird to custom at 600k MAU

A consumer marketplace client crossed 600k MAU on SendBird and watched their chat bill grow faster than revenue. Their differentiator wasn’t chat — but chat costs were eating margin. Their team had two choices: renegotiate, or migrate.

We modelled both. The renegotiated SendBird tier saved ~30%; a custom Node.js + Centrifugo stack hosted on Hetzner with Postgres + Redis modelled out at ~40% of SendBird’s renegotiated price — even after fully-loaded engineering and on-call costs. The win: ten weeks of focused build, a parallel run with traffic mirroring, and a clean cutover. Six months in, gross margin per MAU is up by 22 points and the team owns the moderation rules they could never customise on SendBird.

The lesson isn’t “always go custom.” It’s that the SaaS-vs-custom math flips somewhere between 300k and 1M MAU depending on your features — and most teams discover the flip too late.

When custom chat is the wrong choice

If chat is a feature inside a product whose differentiator is elsewhere, your projected MAU stays under ~300k for the next 18 months, and you don’t have HIPAA-grade requirements, custom is almost certainly wrong. Pay SendBird or Stream, ship in two weeks, ship the differentiator with the time you saved.

Likewise, if your team has no realtime experience and no plan for on-call, custom chat will eat your roadmap. Build the muscles on a less-critical realtime feature first.

FAQ

Is Firebase scalable for chat at 1M MAU?

Technically yes — Firestore can handle the throughput — but the per-read pricing model is unkind to chat’s many small reads. At October 2026 list prices ($0.03 per 100,000 reads, $0.09 per 100,000 writes) the Firestore operations line for a typical 1M-MAU chat is around $700 a month in our worked example; big groups, wide listeners, Cloud Functions and egress push the total higher. Most teams that started on Firebase end up either heavily denormalising, sharding, or migrating to a SaaS or custom stack between 300k and 1M MAU.

What are the best SendBird alternatives?

Stream Chat is the closest like-for-like alternative; PubNub and Ably suit teams that build their own chat layer; CometChat and Agora Chat have lower entry prices; Firebase or Supabase work when chat sits on your own database; Matrix fits self-hosted, federated E2EE chat. Compare list prices in the table above, then negotiate.

Which chat SDK is best for a mobile-first marketplace with moderation?

Stream and SendBird both ship native iOS, Android, React Native and Flutter SDKs with built-in moderation queues, which is what marketplaces need for buyer–seller chat. Pick on price at your MAU and on how much control you need over moderation rules; if rules are very business-specific, a custom backend wins.

When does SendBird get expensive?

Pricing is MAU-based with feature add-ons (advanced moderation, video, broadcast, E2EE). Public plans start at $349 a month billed annually for 5,000 MAU (October 2026), and everything above the listed tiers is an Enterprise quote. Most teams renegotiate around 250k–500k MAU, and the custom-build math starts to win above ~500k MAU for products where chat is critical. Verify with current quotes; tiers and discounts move.

Can you add end-to-end encryption on Firebase?

Not natively. You can encrypt message bodies client-side using a library like libsignal before writing to Firestore, while metadata (who messaged whom, timestamps) stays visible. It’s a 2–4 week project to get right and adds complexity in key management, search and moderation. For E2EE-by-default, custom builds and SendBird’s premium tier are the cleaner paths.

What does it realistically cost to build chat from scratch?

A credible MVP — 1:1 + group, presence, push, moderation, attachments, search, retention — ships in 6–10 weeks with a small senior team using Agent-Engineering tooling. Add 4–8 weeks for E2EE, or per regulatory framework. Operational cost depends on cloud choice and traffic shape; our hosting comparison walks through realistic envelopes.

How long does a Firebase → SendBird (or vice-versa) migration take?

For a chat with mainstream features and <500k MAU, plan 4–8 weeks of engineering plus 2–4 weeks of parallel-run with traffic mirroring. The risky parts are message-history migration, attachment URL rewrites, and push-token re-association. The migration cost is usually paid back inside 6–12 months from the new economics or lifted compliance posture.

Is Socket.io still the right WebSocket library in 2026?

For Node.js shops, yes. It’s mature, still maintained (version 4.8.4 shipped in September 2026 on npm), and has good fallbacks. If you’re willing to leave Node, Centrifugo (Go) and Phoenix Channels (Elixir) hold significantly more concurrent connections per node and are friendlier to operate at scale. Pick by team skill, not nostalgia.

Can you reuse the same chat backend for video chat?

Chat and video are usually layered: chat over WebSocket / SDK; video over WebRTC / SFU (LiveKit, Janus, mediasoup). SendBird and Twilio bundle both. On a custom build, run them as separate services and connect via shared identity, presence and signalling. Agora alternatives covered here.

What about Matrix / federated chat?

Matrix (via Synapse, Dendrite, Conduit) is the right answer when you need data sovereignty, federation across organisations, or E2EE-by-default with no vendor in the trust path. The trade-off is operational complexity: running a Matrix homeserver at scale is non-trivial. Reach for it in defence, public sector, or large multinationals; not for a consumer SaaS chat.

What to Read Next

Ready to pick the right chat backend?

If chat is a feature, ship on SendBird or Stream and revisit at 250k MAU. If chat is the product, plan a custom Node.js + Socket.io (or Go + Centrifugo) stack from day one and budget the operational tail. Firebase still has a place — for mobile-first early-stage apps that won’t cross 300k MAU before a Series A.

The mistake we see most often is choosing on time-to-MVP alone and discovering the SaaS bill or feature ceiling at the wrong moment. Run the unit-economics math; ship for where you’ll be in 18 months, not where you are this sprint.