In-app chat SDKs give a mobile or web product its own messaging layer, covering channels, group rooms, read state and push, without writing a message backend.
We rank them on first-ninety-day integration effort, the bill as active users and connections grow, how history leaves the platform, independence from partners, and fit for product teams.
Vendors can pay for more visibility on this website, for example a higher place in a ranking or more room on a page. Commercial relationships can also affect which products we feature and how prominently. Every vendor link is marked the same, whatever the arrangement behind it. How that works.
In short
What in-app chat sdks software does
An in-app chat SDK is a client library plus a hosted or self-run backend that adds one-to-one and group messaging, presence and notifications to an application you already build.
Ranking criteria for this in-app chat sdks tool list, applied top to bottom: effort to get started, cost in practice, data return, ability to leave, buyer fit. Vendors outside the best-known names fill places 1 to 3 when they exist, and the big brands rank from place 4. Reasons for the choice of tests, and for skipping a score out of ten, can be read on the how we work page.
Free Spark plan with project quotas; Blaze is pay-as-you-go and billed on usage
Yes
Small apps that want to hand-build chat on existing Firebase services
Buyers wanting moderation, receipts and typing indicators supplied
The country column shows the vendor's headquarters or contracting entity. Data hosting is a separate matter, and an entry flags it when the two diverge.
Dutch chat SDK billed on monthly active users with unlimited messages
Ranked #1 of 13 in Best In-App Chat SDKs in 2026.
Pricing on requestEurope
TalkJS prices in USD on monthly active users: Basic covers 10,000 users and Growth 25,000, with extra users at a few cents each and Enterprise on request. Messages and conversations are unlimited, so heavy chatters cost no more than quiet ones.
The homepage lists voice messages, translation, webhooks and AI agent integration. Delivery is hosted in the EU by the vendor, and a self-hosted option is not shown, so teams with strict data-centre rules should look elsewhere.
What stands out
Unlimited messages
EU-hosted
Dev mode
Where it costs you
Group chats top out at 100 participants on Basic and 300 on Growth, which strains community-style rooms.
Taking a project live needs a card on file, so even an internal pilot meets billing.
Right for
Product teams wanting a ready chat interface and a bill that follows user numbers
Wrong for
Teams needing the messaging backend on their own servers
NetherlandsMonthly USD tiers on active users; a development mode runs without a time limit until launch
Low-priced chat and video API with a free tier and dedicated servers
Ranked #2 of 13 in Best In-App Chat SDKs in 2026.
Free tierPublished pricingElsewhere
ConnectyCube sells monthly subscriptions sized by users: Free at 1,000 users and 5 GB, then Hobby, Advanced, Pro and Enterprise, with Enterprise on a dedicated server. Cloud hosting runs on AWS, Microsoft Azure and Google Cloud Platform, and an on-premises option is listed.
Beyond chat it names calling, bots and conversational AI. Participant limits per group rise from 10 to 250 plus, so check the room size you need against the tier before choosing.
What stands out
User-count tiers
Dedicated server
Chat and video
Where it costs you
Free-tier group chats allow only 10 participants and one month of retention.
Server-side recording is limited to Pro and above.
Right for
Startups wanting chat plus video calling on a ladder of cheap, user-based tiers
Wrong for
Buyers who need the vendor's ownership and location confirmed
Not stated by the vendorFree tier, then monthly subscriptions in published tiers by user count; dedicated server on Enterprise
Chat SDK with AI moderation and an on-premise deployment option
Ranked #3 of 13 in Best In-App Chat SDKs in 2026.
Free tierSelf-hostablePublished pricingElsewhere
CometChat lists one-to-one, group and broadcast messaging, search, rich media, quoted replies, typing indicators, read receipts and AI moderation. The Build plan is free for 100 users, Sandbox is free for 1,000 users, and Basic and Advanced are billed annually per active user.
On-premise deployment is named as a platform feature, and a self-hosted team messenger exists. Enterprise starts from 10k users on quote, which is where most growth stories land.
What stands out
On-prem option
AI moderation
Dual metering
Where it costs you
Overage is charged separately for users and for concurrent connections, so two meters can overrun.
AI Agent credits are a further meter, sold in bundles after the monthly allowance.
Right for
Teams wanting prebuilt chat features with a path to on-premise deployment
Wrong for
Buyers who want one flat figure for a whole year
Not stated by the vendorFree Build tier, then annual tiers on active users with overage charges per user and per connection
Indian chat and calling SDK sold as a one-time licence
Ranked #4 of 13 in Best In-App Chat SDKs in 2026.
Self-hostablePricing on requestAsia-Pacific
MirrorFly describes a one-time lifetime licence billed only once, obtained through custom pricing or a booked demo. The homepage offers deployment on your own on-premise server and lists private and group chats, large file uploads, join-by-link and chat moderation.
The footer names Contus Tech Private Limited in Chennai, India. Because there are no posted figures, you must model the licence against the hosting and staff time that owning the stack brings.
What stands out
One-time licence
On-premise deploy
Custom quote
Where it costs you
No price is posted, so budget comparison waits for a sales call.
The vendor offers a demo but states that there is no trial, which limits hands-on testing.
Right for
Companies that prefer paying once and running chat on their own server
Wrong for
Teams wanting self-serve signup with prices visible in advance
IndiaQuoted per project as a one-time licence; a demo is offered in place of a trial
Chat API tiered by monthly active users and concurrent connections
Ranked #5 of 13 in Best In-App Chat SDKs in 2026.
Free tierPublished pricingElsewhere
Stream publishes chat pricing in USD with yearly and monthly options. Build is free for 1,000 users, Start gives 10,000 users and 500 connections, Elevate raises limits and Enterprise is custom.
Overage is priced per extra user, per connection and per million stored messages. Start allows up to 5M stored messages and 500K channels. A Maker account adds a monthly credit for small, low-revenue teams. No trial of the paid plans is mentioned.
What stands out
MAU tiers
Maker credit
Overage rates
Where it costs you
The first paid tier costs far more than the free Build plan, with 10,000 users included.
Extra concurrent connections and stored messages are billed separately from the user count.
Right for
Funded product teams that expect fast user growth and want predictable overage maths
Wrong for
Hobby projects needing something between the free tier and a hefty plan
Not stated by the vendorFree Build tier, then Start and Elevate billed yearly or monthly, with overage per user, connection and stored message
Chat platform with a no-cost trial plan and annual billing discounts
Ranked #6 of 13 in Best In-App Chat SDKs in 2026.
Pricing on requestElsewhere
Sendbird's pricing page shows a trial plan for up to 1,000 users with no overages, then Starter and Pro monthly plans that each start at 5K users and are cheaper when billed annually.
Both paid plans bundle 30K in-app business messages. Enterprise is by contact. The page gave us little else, so features, hosting and limits beyond the connection count need confirming with the vendor before a decision rests on them.
What stands out
Trial plan
MAU tiers
Business messages
Where it costs you
Beyond the trial plan the cheapest tier starts at 5K users, a large jump from 1,000.
Our sources show no country for the company, so jurisdiction questions stay open.
Right for
Teams that want to try chat at no cost before a paid plan
Wrong for
Pilots needing more than 20 peak concurrent connections without paying
Not stated by the vendorFree trial plan, then Starter and Pro tiers priced monthly on active users; Enterprise by quote
Realtime messaging platform with queues, Kafka connectors and an uptime objective
Ranked #7 of 13 in Best In-App Chat SDKs in 2026.
Free tierPublished pricingEurope
Ably's features page names message queues that distribute in order across consumers, a Kafka Connector, streaming out to Kafka, Kinesis, AMQP, SQS and Pulsar, and LiveSync for publishing database changes to clients.
Plans are monthly and tiered by active users, from Free at 500 users to Pro with a 99.999 percent uptime objective and Business with SLAs and a HIPAA BAA. Only the managed platform is described.
What stands out
Message queues
Kafka connector
Uptime SLO
Where it costs you
Chat building blocks are absent from the features page, so threads and receipts need your own work.
Only the 1K-user prices are written out; larger sizes sit behind a slider.
Right for
Engineering teams that need dependable realtime delivery into existing data pipelines
Wrong for
Teams wanting a finished chat interface out of the box
United KingdomFree tier up to 500 active users, then Pro and Business priced monthly on active users; Enterprise quoted
Realtime network with a free tier counted in users or transactions
Ranked #8 of 13 in Best In-App Chat SDKs in 2026.
Free tierPublished pricingElsewhere
PubNub's Free plan includes 1GB of storage and either 200 users or one million transactions. Starter begins at 1,000 users, and Pro is custom from 10M users, with sample prices rising steeply through 5,000, 10,000, 25,000 and 50,000 users.
The FAQ places 100,000 users at about $3,000 monthly. A trial of the Illuminate add-on lasts two weeks. Company pages list four offices but no named country of establishment.
What stands out
Transaction caps
Illuminate trial
MAU ladder
Where it costs you
Free usage is capped at 200 users, far below most rivals' entry tiers.
Pro examples on the page do not state a billing period, which clouds the comparison.
Right for
Developers who want to meter usage by transactions as well as users
Wrong for
Budget planners who need a stated headquarters and clear billing periods
Not stated by the vendorFree tier capped by users or transactions, then Starter and Pro priced monthly on active users
Managed WebSocket channels with presence and a sandbox plan
Ranked #9 of 13 in Best In-App Chat SDKs in 2026.
Free tierPublished pricingElsewhere
The Channels page promises managed WebSocket connections, from one to millions, with automatic fallbacks. It names presence channels, a queryable API for application state, channel information and presence users, and webhooks for client events.
A Sandbox plan gives 200k messages a day. Larger hosted plans and enterprise custom plans are mentioned, but no prices were readable. Self-hosted deployment is not described, so Pusher suits teams happy to rent the transport.
What stands out
WebSocket channels
Presence
Sandbox plan
Where it costs you
The Sandbox ceiling is 100 concurrent connections, which a busy chat will pass.
Plan prices and company location could not be read from the vendor's pages.
Right for
Developers adding live updates and presence to an app with their own message store
Wrong for
Teams wanting threads, read receipts and moderation supplied by the vendor
Not stated by the vendorFree Sandbox plan with daily message and connection caps; hosted and enterprise plans beyond it
Self-managed messaging server with federation and sovereign hosting choices
Ranked #10 of 13 in Best In-App Chat SDKs in 2026.
Self-hostablePricing on requestElsewhere
The Rocket.Chat homepage lists self-hosted, air-gapped and EU-hosted sovereign deployments, plus server-to-server federation with Matrix and XMPP. It also names Zero Trust and post-quantum encryption and a Teams bridge limited to the low side.
A marketplace is labelled coming soon, and a repository link appears without a licence named. The pricing page describes a self-managed workspace at no cost and quoted plans for commercial, government and defence use.
What stands out
Self-hosted
Federation
Air-gapped
Where it costs you
The pages show no embeddable SDK, so in-app use needs checking.
All three paid plans are quote-only, with no prices or currency shown.
Right for
Organisations wanting to run their own messaging server, possibly federated
Wrong for
Product teams looking for a drop-in API with posted prices
Not stated by the vendorQuoted on three enterprise plans; a self-managed workspace carries no charge
MIT-licensed library for WebSocket events with reconnection and fallback
Ranked #11 of 13 in Best In-App Chat SDKs in 2026.
Open sourcePricing on requestElsewhere
Socket.IO's homepage describes WebSocket as the usual transport with fallback to HTTP long-polling, automatic reconnection after a dropped connection, and scaling to multiple servers so events reach every connected client.
Its GitHub repository carries the MIT licence. The site shows no plans or prices, and only a copyright line identifies the project. Cost is therefore your own servers and engineering hours, spent before a first message ever appears.
What stands out
Open source
Long-polling fallback
Library only
Where it costs you
It ships no history, receipts, moderation or push, so each is a project of your own.
Scaling over several servers puts the adapter and hosting decisions on you.
Right for
Developers who want a small MIT-licensed transport and will write the chat logic
Wrong for
Teams needing a vendor with support, an SLA or a named company
Not stated by the vendorOpen source library under the MIT licence; the site lists no plans or prices
Per-user metered conversations API reaching SMS and WhatsApp
Ranked #12 of 13 in Best In-App Chat SDKs in 2026.
Free tierPublished pricingElsewhere
Conversations counts each user once a month by unique address or identity. The first 200 are free, 201 to 5,000 cost five cents each, and the rates fall in bands to 20,000, with custom pricing above.
Media storage starts at 25 cents per GB per month. The page offers Start for free and Contact sales buttons. We could not load the product page, so features are not described here.
What stands out
Per-user bands
SMS and WhatsApp
Media storage
Where it costs you
SMS, MMS and WhatsApp rates, carrier fees and number rentals are charged separately and unpriced on the page.
Above 20,000 active users the price depends on a sales conversation.
Right for
Businesses messaging customers across app, SMS and WhatsApp from one API
Wrong for
Apps with only in-app chat and no wish to pay for channels
Not stated by the vendorFree for the first 200 active users, then falling per-user rates in bands; media storage and carrier fees separate
Build-it-yourself chat on Firestore, Realtime Database and Cloud Messaging
Ranked #13 of 13 in Best In-App Chat SDKs in 2026.
Free tierPublished pricingElsewhere
Firebase's pricing page says there is no dedicated chat product. Chat is assembled from Cloud Firestore, Realtime Database, Cloud Functions and Cloud Messaging, which is listed as no-cost.
Realtime Database offers realtime syncing for JSON data, offline use that syncs on reconnect, and user-based security rules. Blaze raises the connection limit to 200K per database and bills storage beyond 1 GB. Your own code supplies every chat feature.
What stands out
No chat product
Firestore
Blaze plan
Where it costs you
Spark allows 100 simultaneous Realtime Database connections, which a lively chat exhausts.
Firestore's free quotas, such as 50K reads a day, can disappear quickly in message lists.
Right for
Small apps that want to hand-build chat on existing Firebase services
Wrong for
Buyers wanting moderation, receipts and typing indicators supplied
Not stated by the vendorFree Spark plan with project quotas; Blaze is pay-as-you-go and billed on usage
An in-app chat SDK is a client library plus a hosted or self-run backend that adds one-to-one and group messaging, presence and notifications to an application you already build. Work through these questions in order; they separate the products better than a feature matrix does.
01
Work out how much a sales call is worth to you
5 vendors on this page sell by quote, while 8 publish a pricing model you can read today: ConnectyCube, CometChat, Stream, Ably, PubNub, Pusher, Twilio Conversations, Firebase.
02
Look at where the vendor sits
The vendors on this page are based in 4 countries (Elsewhere 10, Europe 2, Asia-Pacific 1). The country of the contracting company sets which authorities can ask it for your data, whatever the hosting region.
03
Check the open source options
1 of these are open source: Socket.IO. Hosting one yourself trades a subscription for maintenance.
Metering in in-app chat SDKs: active users, connections and stored messages
Each vendor here counts something different, so the same app produces very different bills. TalkJS bills on monthly active users and leaves messages unlimited. Stream adds a second and third meter: concurrent connections and stored messages beyond the allowance. CometChat sets concurrent connections at 5 percent of active users and charges overage on both, while Twilio Conversations counts a unique identity once a month and cuts the rate in bands.
Before you shortlist, estimate three numbers from your analytics: monthly active users, peak simultaneous sessions and messages kept. Then run each plan with overage included at double your expected size. The product with the lowest entry price is often not the one with the lowest price at your second year.
Estimate monthly active users, peak concurrent sessions and stored messages
Price each plan at twice your expected size, overage included
Ask whether a user is counted once per month or per channel
ConnectyCube, MirrorFly and CometChat when the backend must sit on your servers
Most chat SDKs are hosted by the vendor, and a few listed here are not. ConnectyCube puts Enterprise customers on a dedicated server and lists an on-premises option, MirrorFly advertises deployment on your own on-premise server under a one-time licence, and CometChat names on-prem deployment as a platform feature. Rocket.Chat goes further with self-hosted and air-gapped installs, and Socket.IO is an MIT library you run entirely yourself.
TalkJS, by contrast, describes a hosted service in the EU. Owning the server removes some vendor risk but moves patching, scaling and incident response onto your staff. Decide who carries the pager before comparing licence costs, and ask each vendor in writing which features differ between its hosted and on-premise builds, because the two are not always identical.
Write down why the data cannot live on the vendor's cloud
Name the person who patches and scales the chat servers
Ask the vendor which features differ between hosted and on-premise builds
Pusher, Ably and Socket.IO: transport layers are not finished chat
Some candidates in this list deliver messages but do not ship a chat product. Pusher Channels offers WebSocket connections, presence channels and webhooks, Ably lists queues, Kafka connectors and LiveSync, and Socket.IO supplies events, reconnection and fallback. Firebase says outright that it has no dedicated chat product.
With any of them, threads, read receipts, moderation, search and push notifications become work for your developers, and that work belongs in the ninety-day setup estimate. Compare them against Stream, Sendbird or TalkJS by listing the chat features your users expect, then counting how many each option supplies on day one. A cheap transport can become the costliest route once those developer weeks are priced honestly, and the answer often changes the order of your shortlist.
List the chat features users expect on launch day
Mark which ones each vendor supplies and which you must code
Add developer weeks for the unchecked items to the real price
Free tiers in chat SDKs: Sendbird, PubNub, Stream and ConnectyCube compared
A free plan only proves the integration, and these limits differ sharply. Sendbird's trial plan allows 1,000 monthly users and 20 peak concurrent connections. Stream's Build tier allows 1,000 users and 100 connections. PubNub stops at 200 users or one million transactions, and ConnectyCube's Free plan limits group chats to 10 participants with one month of retention.
TalkJS runs a development mode with no time limit but asks for a card before launch. None of these figures predicts how an app behaves under launch traffic. Test the free plan with the connection pattern of your real product, then read what happens at the cap: blocked messages, a forced upgrade or silent overage.
Load-test the free plan with your expected concurrent sessions
Confirm what the vendor does when the cap is hit
Check data retention on the plan you test, not the plan you plan to buy
What goes wrong most often when buying in-app chat sdks software
Comparing entry prices instead of the bill at your second-year user count, when overage and connection charges decide the total.
Treating Pusher, Ably, Socket.IO or Firebase as chat products and discovering late that threads and receipts are unbuilt.
Choosing an on-premise option such as MirrorFly or CometChat without budgeting the staff who will patch it.
Accepting a free-plan demo as proof that a chat backend survives your launch-day concurrent connections.
07
Frequently asked questions
8 answers
What is the best in-app chat sdks in 2026?
TalkJS takes first place among the 13 we reviewed. TalkJS is run by Klets B.V. from Eindhoven and bills by monthly active users, with messages and conversations unlimited on every plan.
A month's cost can therefore be predicted from user numbers alone. The limits are group sizes, 100 participants on Basic, and delivery that is only hosted by the vendor. Going live also requires card details, even for a modest launch.
Which in-app chat sdks tools publish their pricing?
8 of the 13, with the pricing model each one publishes:
ConnectyCube: Free tier, then monthly subscriptions in published tiers by user count; dedicated server on Enterprise.
CometChat: Free Build tier, then annual tiers on active users with overage charges per user and per connection.
Stream: Free Build tier, then Start and Elevate billed yearly or monthly, with overage per user, connection and stored message.
Ably: Free tier up to 500 active users, then Pro and Business priced monthly on active users; Enterprise quoted.
PubNub: Free tier capped by users or transactions, then Starter and Pro priced monthly on active users.
Pusher: Free Sandbox plan with daily message and connection caps; hosted and enterprise plans beyond it.
Twilio Conversations: Free for the first 200 active users, then falling per-user rates in bands; media storage and carrier fees separate.
Firebase: Free Spark plan with project quotas; Blaze is pay-as-you-go and billed on usage.
The other 5 quote per organisation.
Is there a free in-app chat sdks tool?
ConnectyCube, CometChat, Stream, Ably, PubNub, Pusher, Twilio Conversations, Firebase have a free plan or free self-hosted edition.
Where are these in-app chat sdks vendors established?
The headquarters are spread over 4 countries and 3 regions, Elsewhere 10, Europe 2, Asia-Pacific 1:
TalkJS: Netherlands.
ConnectyCube: Not stated by the vendor.
CometChat: Not stated by the vendor.
MirrorFly: India.
Stream: Not stated by the vendor.
Sendbird: Not stated by the vendor.
Ably: United Kingdom.
PubNub: Not stated by the vendor.
Pusher: Not stated by the vendor.
Rocket.Chat: Not stated by the vendor.
Socket.IO: Not stated by the vendor.
Twilio Conversations: Not stated by the vendor.
Firebase: Not stated by the vendor.
Which in-app chat sdks tools are open source?
Socket.IO.
Which in-app chat sdks tools can you host yourself?
CometChat, MirrorFly, Rocket.Chat. The other 10 are hosted by the vendor only.
What should you use instead of TalkJS?
Look at ConnectyCube (made for Startups wanting chat plus video calling on a ladder of cheap, user-based tiers) and CometChat (made for teams wanting prebuilt chat features with a path to on-premise deployment), which hold places two and three.
Who should not buy TalkJS?
Teams needing the messaging backend on their own servers. Group chats top out at 100 participants on Basic and 300 on Growth, which strains community-style rooms..
We rank 13 in-app chat sdks products on this page. If we missed one, its maker can write to us about its purpose and customers. We pick what gets added; the terms of a listing are set out under software advice.
