--- title: "JMeter 5.5 Release Notes" description: "Apache JMeter 5.5 release notes with 21 improvements and 32 bug fixes, plus upgrade notes from the official changelog." url: https://docs.jmeter.ai/releases/5-5/ lastUpdated: 2026-10-01 source: docs.jmeter.ai --- # JMeter 5.5 Release Notes > **About these release notes** > This page lists every documented change shipped in Apache JMeter 5.5, generated from the official changelog. For download and upgrade guidance, see [Download JMeter](/reference/download-jmeter/). ## Change summary | Section | Changes | | --- | --- | | Improvements | 21 | | Bug fixes | 32 | | Non-functional changes | 55 | ## New and Noteworthy JMeter now supports Java 17 JMeter 5.5 ships with log4j2 2.17.2 ### Open Model Thread Group New component: `[Open Model Thread Group](/./usermanual/component-reference/#Open_Model_Thread_Group)` allows creating load profiles with variable load. For example, if you need to gradually increase load from `0/sec` to `10/sec` during `minute` you could previously use `Thread Group + Timer` combinations. However, then you need to compute the expected number of threads, ensure they are created only when needed, and so on. With `Open Model Thread Group` you can configure the same load profile as `rate(0/sec) random_arrivals(1 minute) rate(10/sec)`. The thread group would spawn threads as needed to drive the configured load. The load profile can use properties, so you can launch the same script with slightly different load levels, however, the profile can’t be updated while the test is running. The new thread group is experimental in JMeter 5.5, so please feel free to submit your feedback. ![Open Model Thread Group sample](/images/screenshots/open_model_thread_group.png) *Open Model Thread Group sample* ### Preparing the deprecation of Oro Regex usage Another experimental feature in JMeter 5.5 is the ability to replace the Oro based Regex implementation by the built-in Java based one. To choose the Java based one, set the JMeter property `jmeter.regex.engine` to the value `java`. ### Core improvements Kotlin language is now used in some core classes and tests (e.g. Open Model Thread Group). JMeter is compiled with `apiTarget=1.5`, and it ships with `kotlin-stdlib` 1.6. [lets-plot-kotlin](https://github.com/JetBrains/lets-plot-kotlin) charting library is added, so it will be easier to refine and create new charts in UI in the future. ## Improvements #### Thread Groups - New component: `[Open Model Thread Group](/./usermanual/component-reference/#Open_Model_Thread_Group)` #### HTTP Samplers and Test Script Recorder - [Bug 65027](https://bz.apache.org/bugzilla/show_bug.cgi?id=65027)Detect mime-type for files automatically when adding files to HTTP Sampler - [Bug 65020](https://bz.apache.org/bugzilla/show_bug.cgi?id=65020)HTTP Sampler/Files upload tab - add missing buttons - [PR#650](https://github.com/apache/jmeter/pull/650)HTTP Sampler timestamp fix when exception is caught. Contributed by Konstantin Kalinin (konstantin at kkalinin.pro) - [Bug 65328](https://bz.apache.org/bugzilla/show_bug.cgi?id=65328)[PR#666](https://github.com/apache/jmeter/pull/666)HTTP 308 Permanent Redirect is not supported. Contributed by Baptiste Gaillard (baptiste.gaillard at gmail.com) #### Other samplers - [Bug 65149](https://bz.apache.org/bugzilla/show_bug.cgi?id=65149)[PR#644](https://github.com/apache/jmeter/pull/644)Encode the personal part of email addresses in SMTP Sampler - [PR#638](https://github.com/apache/jmeter/pull/638)Various additions to the Bolt Sampler. Added `transaction timeout`, `database` option required for Neo4j 4.x (with multi-database support) and `access mode` option, that allows running against a Neo4j Enterprise Causal Cluster. Contributed by David Pecollet (david.pecollet at gmail.com) #### Controllers - [PR#665](https://github.com/apache/jmeter/pull/665)Increase visible lines of code in `IfController` and `WhileController`. Based on an idea by David Getzlaff (david.getzlaff at t-systems.com>). #### Listeners - [Bug 64988](https://bz.apache.org/bugzilla/show_bug.cgi?id=64988)Sort properties and variables in a human expected order for DebugPostProcessor and DebugSampler - [Bug 63061](https://bz.apache.org/bugzilla/show_bug.cgi?id=63061)Sort View Results in Table in a human expected order - [PR#706](https://github.com/apache/jmeter/pull/706)Try to keep UI responsive when displaying large text results. Can be configured with the new property `view.results.tree.simple_view_limit` #### Timers, Assertions, Config, Pre- & Post-Processors - [PR#638](https://github.com/apache/jmeter/pull/638)Bolt Connection Configuration: added `ConnectionPoolMaxSize` parameter. Contributed by David Pecollet (david.pecollet at gmail.com) - [Bug 65515](https://bz.apache.org/bugzilla/show_bug.cgi?id=65515)Allow pooling of Prepared Statements in JDBC - [Bug 65299](https://bz.apache.org/bugzilla/show_bug.cgi?id=65299)JSONPathAssertion attributes are out of order/Compare JSON objects and not their string representations. #### Report / Dashboard - [Bug 65353](https://bz.apache.org/bugzilla/show_bug.cgi?id=65353)Make the estimator used for calculating percentiles on the dashboard configurable #### General - [Bug 61805](https://bz.apache.org/bugzilla/show_bug.cgi?id=61805)[PR#663](https://github.com/apache/jmeter/pull/663)Add simple HTTP request template. Contributed by Ori Marko (orimarko at gmail.com) - [Bug 65611](https://bz.apache.org/bugzilla/show_bug.cgi?id=65611)[PR#673](https://github.com/apache/jmeter/pull/673)Add support for IPv6 addresses when specifying a remote worker node. Based on a patch by Peter Wong (peter.wong at csexperts.com) - Reduce memory consumption by the logging panel (disable undo events for it) - [Bug 63620](https://bz.apache.org/bugzilla/show_bug.cgi?id=63620)[PR#694](https://github.com/apache/jmeter/pull/694)Fix GUI freeze when viewing response body with long line breaks - [PR#699](https://github.com/apache/jmeter/pull/699)Add documentation for Graphite Backend Listener. Contributed by Ji Hun (jihunkimkw at gmail.com) - [Bug 57672](https://bz.apache.org/bugzilla/show_bug.cgi?id=57672)[PR#700](https://github.com/apache/jmeter/pull/700)Add a switch (`jmeter.regex.engine`) to replace Oro Regex implementation by the built-in Java one. ## Bug fixes #### HTTP Samplers and Test Script Recorder - [Bug 65310](https://bz.apache.org/bugzilla/show_bug.cgi?id=65310)Don’t let users override `multipart/form-data` `content-type` header in HC4 sampler. - [Bug 65363](https://bz.apache.org/bugzilla/show_bug.cgi?id=65363)`NullPointerException` in `HTTPHC4Impl$ManagedCredentialsProvider.getAuthorizationForAuthScope` when `401` response from remote and `httpclient4.auth.preemptive=false` - [Bug 65692](https://bz.apache.org/bugzilla/show_bug.cgi?id=65692)HTTP(s) Test Script Recorder: Enable setting enabled cipher suite and enabled protocols on SSLContext/ Align SSL properties between Java and HC4 implementation - [Bug 65108](https://bz.apache.org/bugzilla/show_bug.cgi?id=65108)Support JMeter variables in [GraphQL HTTP Request](/./usermanual/component-reference/#HTTP_Request) - [Bug 65864](https://bz.apache.org/bugzilla/show_bug.cgi?id=65864)Catch `NullPointerException` from JSoup when recording a test plan #### Other Samplers - [Bug 65152](https://bz.apache.org/bugzilla/show_bug.cgi?id=65152)OS Process Sampler - Cannot `Add from Clipboard` Command parameters - [PR#638](https://github.com/apache/jmeter/pull/638)Bolt Sampler: fixed error displaying results when “Record Query Results” is enabled. Contributed by David Pecollet (david.pecollet at gmail.com) #### Controllers #### Listeners - [Bug 64962](https://bz.apache.org/bugzilla/show_bug.cgi?id=64962)Save CSV sub-results recursively from View Results Tree - [Bug 65784](https://bz.apache.org/bugzilla/show_bug.cgi?id=65784)No Graphs displayed in Aggregate Report/Response Time Graph - [Bug 65884](https://bz.apache.org/bugzilla/show_bug.cgi?id=65884)GUI doesn’t display response for multipart request *manually* encoded #### Timers, Assertions, Config, Pre- & Post-Processors - [Bug 65257](https://bz.apache.org/bugzilla/show_bug.cgi?id=65257)JMESPathExtractor writes error log entries if JMESPath filter returns empty result - [Bug 65259](https://bz.apache.org/bugzilla/show_bug.cgi?id=65259)JMESPathExtractor Attribute `Match No.` Required - [Bug 65269](https://bz.apache.org/bugzilla/show_bug.cgi?id=65269)JSON Extractor and JSON JMESPath Extractor ignore sub-samples - [Bug 65352](https://bz.apache.org/bugzilla/show_bug.cgi?id=65352)Warning logged when Boundary Extractor doesn’t find any match - [Bug 65681](https://bz.apache.org/bugzilla/show_bug.cgi?id=65681)Use default values for `null` values when extracting with JSONPostProcessor - Allow setters in ConstantThroughputTimer to update the values during run time - [Bug 65782](https://bz.apache.org/bugzilla/show_bug.cgi?id=65782)Use correct message format for MessageFormat in HTMLAssertion - [Bug 65794](https://bz.apache.org/bugzilla/show_bug.cgi?id=65794)JSON Assertion always successful with indefinite paths #### Functions #### I18N #### Report / Dashboard #### Documentation - [PR#658](https://github.com/apache/jmeter/pull/658)Improve javadoc. Contributed by Ori Marko (orimarko at gmail.com) #### General - [Bug 64318](https://bz.apache.org/bugzilla/show_bug.cgi?id=64318)DNS Cache Manager - custom DNS resolver does not use system resolver by default - [PR#641](https://github.com/apache/jmeter/pull/641)[PR#698](https://github.com/apache/jmeter/pull/698)Updated xercesImpl to 2.12.2 (from 2.12.0). Based on patch by Stefan Seide (stefan at trilobyte-se.de). - [PR#645](https://github.com/apache/jmeter/pull/645)Add escaping for new lines in `AbstractInfluxdbMetricsSender`. Contributed by David Getzlaff (david.getzlaff at t-systems.com>) - [Bug 65198](https://bz.apache.org/bugzilla/show_bug.cgi?id=65198)Can’t copy generated function from FunctionHelper - [PR#661](https://github.com/apache/jmeter/pull/661)Fix wording in doc. Contributed by BugKing (wangzhen at fit2cloud.com) - [PR#664](https://github.com/apache/jmeter/pull/664)Allow whitespace in path. Contributed by Till Neunast (github.com/tilln) - [Bug 65270](https://bz.apache.org/bugzilla/show_bug.cgi?id=65270)POST `application/x-www-form-urlencoded` cURL code generated from Postman is not imported correctly - Silence warnings of missing font Arial on startup under Linux - [Bug 65300](https://bz.apache.org/bugzilla/show_bug.cgi?id=65300)`IllegalAccessError` when opening file dialog with Java 16 - [Bug 65336](https://bz.apache.org/bugzilla/show_bug.cgi?id=65336)Blank labels when different elements had the same name - [Bug 65522](https://bz.apache.org/bugzilla/show_bug.cgi?id=65522)Restart doesn’t work, when parameters contain spaces - [Bug 63914](https://bz.apache.org/bugzilla/show_bug.cgi?id=63914)Simplify `:src:dist:clean` configuration, ensure `/lib/junit/test.jar` is removed on clean - [PR#696](https://github.com/apache/jmeter/pull/696)Keep JSyntaxTextArea text value for use in headless mode. Contributed by Peter Paul Bakker (peter.paul.bakker at stokpop.nl) ## Non-functional changes - Added Kotlin 1.6.21 for JMeter engine implementation (apiVersion=1.5). The set of JSR 223 languages is intact. - [Bug 65128](https://bz.apache.org/bugzilla/show_bug.cgi?id=65128)[PR#643](https://github.com/apache/jmeter/pull/643)Add missing documentation about `Same user on each iteration` for Thread Groups. Contributed by njkuzas. - [PR#648](https://github.com/apache/jmeter/pull/648)Updated xmlgraphics-commons to 2.6 (from 2.3). Contributed by Stefan Seide (stefan at trilobyte-se.de) - [PR#655](https://github.com/apache/jmeter/pull/655)[PR#667](https://github.com/apache/jmeter/pull/667)[PR#675](https://github.com/apache/jmeter/pull/675)[PR#698](https://github.com/apache/jmeter/pull/698)Updated x-stream to 1.4.19 (from 1.4.15). Contributed by Stefan Seide (stefan at trilobyte-se.de) - [PR#656](https://github.com/apache/jmeter/pull/656)[PR#668](https://github.com/apache/jmeter/pull/668)Updated json-smart to 2.4.8 (from 2.3), accessors-smart to 2.4.8 (from 1.2) and asm 9.3 (from 9.0). Contributed by Stefan Seide (stefan at trilobyte-se.de) - [Bug 64831](https://bz.apache.org/bugzilla/show_bug.cgi?id=64831)Log truststore entries in debug level for logger `org.apache.jmeter.util.keystore.JmeterKeyStore` - [Bug 65232](https://bz.apache.org/bugzilla/show_bug.cgi?id=65232)Hide splash screen when an error is displayed because the test plan could not be parsed. - Updated Groovy to 3.0.11 (from 3.0.7). - Updated Darklaf to 2.7.3 (from 2.5.4). - Updated Apache ActiveMQ to 15.6.4 (from 15.6.0). - Updated Asm to 9.2 (from 9.1). - Updated Bouncycastle to 1.70 (from 1.67). - Updated Caffeine to 2.9.3 (from 2.8.8). - Updated Apache commons-dbcp2 to 2.9.0 (from 2.8.0). - Updated Apache commons-io to 2.11.0 (from 2.8.0). - Updated Apache commons-lang3 to 3.12.0 (from 3.11). - Updated Apache commons-net to 3.8.0 (from 3.7.2). - Updated Apache commons-pool2 to 2.11.1 (from 2.9.0). - Updated equalsverifier to 3.10 (from 3.4.2). - Updated Apache Freemarker to 2.3.31 (from 2.3.30). - Updated hsqldb to 2.5.2 (from 2.5.0). - Updated Apache HttpClient to 4.5.13 (from 4.5.12). - Updated Apache HttpCore to 4.4.15 (from 4.4.13). - Updated jacoco to 0.8.7 (from 0.8.5). - Updated json-path to 2.7.0 (from 2.4.0). - Updated jsoup to 1.15.1 (from 1.13.1). - Updated JUnit to 4.13.2 and 5.8.2 (from 4.13.1 and 5.7.0). - Updated Apache log4j2 to 2.17.2 (from 2.13.3). - Updated Miglayout to 5.3 (from 5.2). - Updated Neo4j Java driver to 4.4.6 (from 4.2.0). - Updated Objenesis to 3.2 (from 2.6). - Updated ktlint to 0.40.0 - Updated PH CSS and PH commons to 6.5.4 and 10.1.6 (from 6.2.3 and 9.5.1). - Updated RSyntaxTextArea to 3.2.0 (from 3.1.1). - Updated SLF4J to 1.7.36 (from 1.7.30). - Updated SvgSalamander to 1.1.2.4 (from 1.1.2.1). - [PR#698](https://github.com/apache/jmeter/pull/698)Updated Apache Tika to 1.28.3 (from 1.26). - Updated WireMock-JRE8 to 2.30.0 (from 2.24.1). - Updated com.github.vlsi.vlsi-release-plugins 1.76 (from 1.74). - Updated jackson to 2.13.3 (from 2.10.5) - Updated jmespath to 0.5.1 - Updated Saxon-HE to 11.2 (from 9.9.1-8) - Updated Apache xmlgraphics commons to 2.7 (from 2.6) - [PR#671](https://github.com/apache/jmeter/pull/671)Move example definition of property `jmeter.reportgenerator.statistic_window` to `user.properties`, as it is read from that place. Contributed by Rithvik Patibandla (rithvikp98 at gmail.com) - [Bug 65456](https://bz.apache.org/bugzilla/show_bug.cgi?id=65456)Updated commons-jexl 3 to 3.2.1 (from 3.1). Contributed by Ori Marko (orimarko at gmail.com>) - [PR#654](https://github.com/apache/jmeter/pull/654)Try do give better feedback while loading keystores - [PR#672](https://github.com/apache/jmeter/pull/672)Add more details to documentation for timeShift function. Contributed by Mariusz (mawasak at gmail.com) - Updated Gradle to 7.3 (from 7.2) - [PR#689](https://github.com/apache/jmeter/pull/689)Code clean up in StringFromFile. Contributed by Sampath Kumar Krishnasamy (sampathkumar.krishnasamykuppusamy at aexp.com) - [PR#690](https://github.com/apache/jmeter/pull/690)Refactor a few unit tests. Contributed by Sampath Kumar Krishnasamy (sampathkumar.krishnasamykuppusamy at aexp.com) - [PR#692>](https://github.com/apache/jmeter/pull/692%3E)Fix a few deprecation warnings for Gradle. Contributed by Sampath Kumar Krishnasamy (sampathkumar.krishnasamykuppusamy at aexp.com) - [PR#697>](https://github.com/apache/jmeter/pull/697%3E)Junit 5 tests to use asserts from Junit 5 API. Contributed by Sampath Kumar Krishnasamy (sampathkumar.krishnasamykuppusamy at aexp.com) - [Bug 65983](https://bz.apache.org/bugzilla/show_bug.cgi?id=65983)[PR#707](https://github.com/apache/jmeter/pull/707)Use current screenshot for save-to-file listener in documentation. Based on patch by NaveenKumar Namachivayam (catch.nkn at gmail.com) - [PR#708](https://github.com/apache/jmeter/pull/708)Make errorprone happier. Based on patch by Wilson Kurniawan (wilson at visenze.com)> - Updated Rhino JavaScript to 1.7.14 (from 1.7.13) ## Thanks We thank all contributors mentioned in bug and improvement sections above: - Stefan Seide (stefan at trilobyte-se.de) - njzukas (github.com/njzukas) - David Getzlaff (david.getzlaff at t-systems.com>) - Konstantin Kalinin (konstantin at kkalinin.pro) - David Pecollet (david.pecollet at gmail.com) - Ori Marko (orimarko at gmail.com) - BugKing (wangzhen at fit2cloud.com) - Till Neunast (github.com/tilln) - Baptiste Gaillard (baptiste.gaillard at gmail.com) - Rithvik Patibandla (rithvikp98 at gmail.com) - Mariusz (mawasak at gmail.com) - [peter.wong@csexperts.com](mailto:peter.wong@csexperts.com) - Woonsan Ko (woonsan.ko at bloomreach.com) - Chromico Rek (atech5122 at gmail.com) - Magnus Spångdal (magnus.spangdal as avanza.se) - Piotr Smietana (piotrsmietana1998 at gmail.com) - Sampath Kumar Krishnasamy (sampathkumar.krishnasamykuppusamy at aexp.com) - Ji Hun (jihunkimkw at gmail.com) - Peter Paul Bakker (peter.paul.bakker at stokpop.nl) - NaveenKumar Namachivayam (catch.nkn at gmail.com) - Wilson Kurniawan (wilson at visenze.com) We also thank bug reporters who helped us improve JMeter. - Nikola Aleksic (nalexic at gmail.com) - Vladimir Rosu (rosuvladimir at gmail.com) Apologies if we have omitted anyone else. ## Useful links - [Download JMeter](/reference/download-jmeter/) - [Getting started guide](/getting-started/get-started/) - [All release notes](/releases/) - [Current changes page](/user-manual/changes/) - [History of previous changes](/user-manual/changes-history/)