Release notes#
User-facing version history for MQTT.fx. The authoritative source is the in-app release notes (About → Release Notes); this page summarizes them, newest first.
Version 5.14.0 (2026-07-12)#
- New: The Sparkplug Explorer keeps a chronological per-topic message history (last 500 messages) — a Store & Forward replay burst after a connection loss no longer overwrites itself; every message stays visible. See Sparkplug B.
- New: Sparkplug Store & Forward messages (metrics flagged
is_historical) are detected, marked in a Historical column, and highlighted; a Show filter switches between All Messages, Live Only, and Historical Only (Store & Forward). - New: Help → User Manual opens this manual (mqttfx-manual.softblade.net) in the browser.
- Fixed: Sparkplug STATE messages (
spBv1.0/STATE/...) no longer cause an internal error and now show up in the Sparkplug Explorer. - Fixed: The Sparkplug payload decoders produced no output (incompatibility with the Eclipse Tahu 1.0.8 runtime).
- Improved: The Sparkplug Explorer now uses Sparkplug Pretty Format Decoder (Eclipse Tahu) as its default payload decoder.
Version 5.13.1 (2026-06-26)#
- Fixed: The MQTT 5.0 publish/subscribe options (User Properties, Content Type, Payload Format Indicator, Message Expiry Interval, Response Topic, Correlation Data) are now correctly enabled when connected with an MQTT 5.0 session.
- Fixed: The app no longer fails to start when a custom theme was selected without a valid CSS file; it falls back to the default theme instead.
- Improved: Selecting the Custom theme without a valid CSS file no longer persists a broken theme configuration.
Version 5.13.0 (2026-06-08)#
- New: Try MQTT.fx without a license — up to 5 free Demo Sessions, all features, 2 hours each. A session only starts counting with real usage; just opening the app is free. Afterwards a license or the free 30-day trial license is required.
- Improved: Changing message/console buffer sizes in Settings now takes effect for newly subscribed topics without restarting the app.
- Improved: Overall performance, especially under heavy load.
- Fixed: A chosen color for a subscribed topic is now kept across re-subscribes.
- Fixed: Several minor bugs.
Version 5.12.0 (2026-02-06)#
- Improved: Namespace Explorer tree nodes show a shortened payload to avoid performance issues with larger payloads.
- Improved: Backpressure performance tweaks.
- Fixed: Namespace Explorer did not collect the topics list; a Sparkplug Explorer issue.
Version 5.11.0 (2025-12-05)#
- New: Option in the Namespace Explorer to subscribe to alternative topic filters.
- New: Performance tweaks under heavy load.
Version 5.10.x (2025-12)#
- Performance: Improvements to the Subscribe & Receive tab and the Namespace Explorer; new installer and updated runtime.
- TLS: Now uses the default (internal) TrustManagerFactory.
- Subscriptions: Advanced feedback on subscribe, with an error dialog on subscription issues; subscriptions are no longer shown as successful when they fail.
- Fixed: The payload decoder in the Receive tab is sticky again.
Version 5.9.0 (2024-12)#
- New: Namespace Explorer can purge retained messages from topics.
- New: MQTT 5.0 details added to Publish, Subscribe, and the Namespace Explorer.
- New: MQTT 5.0 advanced subscription options — No Local, Retain As Published, Retain Handling.
- Improved: MQTT 5.0 sessions (Clean Start + Session Expiry Interval).
Version 5.7.x (2024)#
- New: Introduced the Namespace Explorer.
- New: Bundled with Java Runtime 21 LTS.
- New: Subscriptions and the Namespace Explorer gained a messages-per-second counter; auto-detection and pretty-printing of JSON and Sparkplug payloads; overload protection.
- New: MQTT.fx Community Edition introduced.
Version 5.2.0 (2022-05-12)#
- New: The Sparkplug B Message Explorer.
- New: PKCS #12 / P12 keystore support; option to trust all hostnames.
- New: Scripting returned, using the GraalVM JavaScript engine (ECMAScript 202x).
- New: Additional payload decoders; message-buffer filtering and JSON export; per- topic message dumps.
Version 5.1.0 (2021-12-24)#
- New: Custom payload editor add-ons; RSA & EC algorithms; auto-reconnect and clean session / clean start; HiveMQ Cloud profile type; table view for messages.
Version 5.0.0 (2021-01-12)#
- New: Integrated the HiveMQ MQTT client for full MQTT 5.0 support; TLS 1.3.
- New: MQTT 5 message properties on publish (User Properties, Content Type) and on receive, with automatic payload-decoder selection based on content type.
Earlier history (1.x)#
The 1.x series (through 2018) established the core MQTT.fx feature set: connection profiles, publish/subscribe, the topics collector, HTTP proxy support, custom decoder add-ons, Sparkplug payload decoding, and the original Google Cloud IoT support.