# Releases

This section summarizes the notable changes of every release and links to the relevant documentation. The **complete release notes** — including all changes, the download files, and their checksums — are published on the [GitHub releases page](https://github.com/nlohmann/json/releases).

Unreleased changes

This documentation is built from the `develop` branch and may describe changes that are not part of a release yet. Their version numbers are followed by an unreleased badge.

Every release has its own page with a summary of its notable changes and an overview of the API that was added or changed in it. The API overview is generated from the "Version history" section of the [API pages](https://json.nlohmann.me/api/basic_json/index.md); it is not a change log, but helps to see whether a feature is available in the version you use.

## Unreleased

| Release                                                                  | Date | Summary                                                             |
| ------------------------------------------------------------------------ | ---- | ------------------------------------------------------------------- |
| [Unreleased](https://json.nlohmann.me/home/releases/unreleased/index.md) |      | Changes on the `develop` branch that are not part of a release yet. |

## Version 3.12.x

| Release                                                            | Date       | Summary                                                                                     |
| ------------------------------------------------------------------ | ---------- | ------------------------------------------------------------------------------------------- |
| [v3.12.0](https://json.nlohmann.me/home/releases/v3.12.0/index.md) | 2025-04-11 | Fixes bugs found in 3.11.3 and adds several features. No public API was removed or renamed. |

## Version 3.11.x

| Release                                                            | Date       | Summary                                                                                         |
| ------------------------------------------------------------------ | ---------- | ----------------------------------------------------------------------------------------------- |
| [v3.11.3](https://json.nlohmann.me/home/releases/v3.11.3/index.md) | 2023-11-28 | Adds features and fixes bugs found in 3.11.2. All changes are backward-compatible.              |
| [v3.11.2](https://json.nlohmann.me/home/releases/v3.11.2/index.md) | 2022-08-12 | Fixes bugs found in 3.11.1 and restructures the namespace. All changes are backward-compatible. |
| [v3.11.1](https://json.nlohmann.me/home/releases/v3.11.1/index.md) | 2022-08-01 | Fixes a regression from 3.11.0. All changes are backward-compatible.                            |
| [v3.11.0](https://json.nlohmann.me/home/releases/v3.11.0/index.md) | 2022-08-01 | One of the largest releases ever. All changes are backward-compatible.                          |

## Version 3.10.x

| Release                                                            | Date       | Summary                                                                                                                                  |
| ------------------------------------------------------------------ | ---------- | ---------------------------------------------------------------------------------------------------------------------------------------- |
| [v3.10.5](https://json.nlohmann.me/home/releases/v3.10.5/index.md) | 2022-01-03 | Bug-fix release. All changes are backward-compatible.                                                                                    |
| [v3.10.4](https://json.nlohmann.me/home/releases/v3.10.4/index.md) | 2021-10-16 | Fixes regressions introduced in 3.10.0. All changes are backward-compatible.                                                             |
| [v3.10.3](https://json.nlohmann.me/home/releases/v3.10.3/index.md) | 2021-10-08 | Fixes more regressions from 3.10.0. All changes are backward-compatible.                                                                 |
| [v3.10.2](https://json.nlohmann.me/home/releases/v3.10.2/index.md) | 2021-08-26 | Re-release of 3.10.1, whose Git tag pointed at the wrong commit due to a bug in the release script. All changes are backward-compatible. |
| [v3.10.1](https://json.nlohmann.me/home/releases/v3.10.1/index.md) | 2021-08-24 | Fixes a regression from 3.10.0. All changes are backward-compatible.                                                                     |
| [v3.10.0](https://json.nlohmann.me/home/releases/v3.10.0/index.md) | 2021-08-17 | Feature release. All changes are backward-compatible.                                                                                    |

## Version 3.9.x

| Release                                                          | Date       | Summary                                                                                   |
| ---------------------------------------------------------------- | ---------- | ----------------------------------------------------------------------------------------- |
| [v3.9.1](https://json.nlohmann.me/home/releases/v3.9.1/index.md) | 2020-08-06 | Fixes two regressions from 3.9.0. All changes are backward-compatible.                    |
| [v3.9.0](https://json.nlohmann.me/home/releases/v3.9.0/index.md) | 2020-07-27 | Feature release adding four long-requested features. All changes are backward-compatible. |

## Version 3.8.x

| Release                                                          | Date       | Summary                                               |
| ---------------------------------------------------------------- | ---------- | ----------------------------------------------------- |
| [v3.8.0](https://json.nlohmann.me/home/releases/v3.8.0/index.md) | 2020-06-14 | Feature release. All changes are backward-compatible. |

## Version 3.7.x

| Release                                                          | Date       | Summary                                                                                                                                                                                                                         |
| ---------------------------------------------------------------- | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [v3.7.3](https://json.nlohmann.me/home/releases/v3.7.3/index.md) | 2019-11-17 | Fixes a regression from 3.7.2 that could yield quadratic complexity in destructor calls. All changes are backward-compatible.                                                                                                   |
| [v3.7.2](https://json.nlohmann.me/home/releases/v3.7.2/index.md) | 2019-11-10 | Fixes a stack overflow for deeply nested input by making the destructor iterative; parsing of JSON text is now bounded only by available memory (the binary-format parsers still recurse). All changes are backward-compatible. |
| [v3.7.1](https://json.nlohmann.me/home/releases/v3.7.1/index.md) | 2019-11-06 | Bug-fix release. All changes are backward-compatible.                                                                                                                                                                           |
| [v3.7.0](https://json.nlohmann.me/home/releases/v3.7.0/index.md) | 2019-07-28 | Convenience features and house-keeping. All changes are backward-compatible.                                                                                                                                                    |

## Version 3.6.x

| Release                                                          | Date       | Summary                                                                                                                            |
| ---------------------------------------------------------------- | ---------- | ---------------------------------------------------------------------------------------------------------------------------------- |
| [v3.6.1](https://json.nlohmann.me/home/releases/v3.6.1/index.md) | 2019-03-20 | Fixes a regression (GCC 7/8 compilation) and a `<Windows.h>` build error introduced in 3.6.0. All changes are backward-compatible. |
| [v3.6.0](https://json.nlohmann.me/home/releases/v3.6.0/index.md) | 2019-03-20 | Feature release. All changes are backward-compatible.                                                                              |

## Version 3.5.x

| Release                                                          | Date       | Summary                                               |
| ---------------------------------------------------------------- | ---------- | ----------------------------------------------------- |
| [v3.5.0](https://json.nlohmann.me/home/releases/v3.5.0/index.md) | 2018-12-22 | Feature release. All changes are backward-compatible. |

## Version 3.4.x

| Release                                                          | Date       | Summary                                               |
| ---------------------------------------------------------------- | ---------- | ----------------------------------------------------- |
| [v3.4.0](https://json.nlohmann.me/home/releases/v3.4.0/index.md) | 2018-10-30 | Feature release. All changes are backward-compatible. |

## Version 3.3.x

| Release                                                          | Date       | Summary                                               |
| ---------------------------------------------------------------- | ---------- | ----------------------------------------------------- |
| [v3.3.0](https://json.nlohmann.me/home/releases/v3.3.0/index.md) | 2018-10-05 | Feature release. All changes are backward-compatible. |

## Version 3.2.x

| Release                                                          | Date       | Summary                                               |
| ---------------------------------------------------------------- | ---------- | ----------------------------------------------------- |
| [v3.2.0](https://json.nlohmann.me/home/releases/v3.2.0/index.md) | 2018-08-20 | Feature release. All changes are backward-compatible. |

## Version 3.1.x

| Release                                                          | Date       | Summary                                               |
| ---------------------------------------------------------------- | ---------- | ----------------------------------------------------- |
| [v3.1.2](https://json.nlohmann.me/home/releases/v3.1.2/index.md) | 2018-03-14 | Bug-fix release. All changes are backward-compatible. |
| [v3.1.1](https://json.nlohmann.me/home/releases/v3.1.1/index.md) | 2018-02-13 | Bug-fix release. All changes are backward-compatible. |
| [v3.1.0](https://json.nlohmann.me/home/releases/v3.1.0/index.md) | 2018-02-01 | Feature release. All changes are backward-compatible. |

## Version 3.0.x

| Release                                                          | Date       | Summary                                                                                                                                                                                                                                                                                |
| ---------------------------------------------------------------- | ---------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [v3.0.1](https://json.nlohmann.me/home/releases/v3.0.1/index.md) | 2017-12-29 | Fixes small issues in the [JSON Pointer](https://json.nlohmann.me/features/json_pointer/index.md) and [JSON Patch](https://json.nlohmann.me/features/json_patch/index.md) implementations (invalid "copy" targets and non-integer array indices). All changes are backward-compatible. |
| [v3.0.0](https://json.nlohmann.me/home/releases/v3.0.0/index.md) | 2017-12-17 | First 3.x release — a major release with breaking changes (see the [migration guide](https://json.nlohmann.me/integration/migration_guide/index.md)).                                                                                                                                  |

## Version 2.1.x

| Release                                                          | Date       | Summary                                               |
| ---------------------------------------------------------------- | ---------- | ----------------------------------------------------- |
| [v2.1.1](https://json.nlohmann.me/home/releases/v2.1.1/index.md) | 2017-02-25 | Bug-fix release. All changes are backward-compatible. |
| [v2.1.0](https://json.nlohmann.me/home/releases/v2.1.0/index.md) | 2017-01-28 | Feature release. All changes are backward-compatible. |

## Version 2.0.x

| Release                                                            | Date       | Summary                                                                                                                                                                                                                                                               |
| ------------------------------------------------------------------ | ---------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [v2.0.10](https://json.nlohmann.me/home/releases/v2.0.10/index.md) | 2017-01-02 | Fixes several security-relevant bugs in the CBOR and MessagePack parsers found by OSS-Fuzz. All changes are backward-compatible.                                                                                                                                      |
| [v2.0.9](https://json.nlohmann.me/home/releases/v2.0.9/index.md)   | 2016-12-16 | Adds the [CBOR](https://json.nlohmann.me/features/binary_formats/cbor/index.md) and [MessagePack](https://json.nlohmann.me/features/binary_formats/messagepack/index.md) binary formats. All changes are backward-compatible.                                         |
| [v2.0.8](https://json.nlohmann.me/home/releases/v2.0.8/index.md)   | 2016-12-02 | Adds the [`emplace`](https://json.nlohmann.me/api/basic_json/emplace/index.md) and [`emplace_back`](https://json.nlohmann.me/api/basic_json/emplace_back/index.md) functions and improves parsing and serialization performance. All changes are backward-compatible. |
| [v2.0.7](https://json.nlohmann.me/home/releases/v2.0.7/index.md)   | 2016-11-02 | Fixes several parser bugs found through the "Parsing JSON is a Minefield" study (short files, encoding detection, surrogate pairs). All changes are backward-compatible.                                                                                              |
| [v2.0.6](https://json.nlohmann.me/home/releases/v2.0.6/index.md)   | 2016-10-15 | Fixes [`operator[]`](https://json.nlohmann.me/api/basic_json/operator%5B%5D/index.md) for [JSON pointers](https://json.nlohmann.me/features/json_pointer/index.md) so that it creates missing values like the other overloads. All changes are backward-compatible.   |
| [v2.0.5](https://json.nlohmann.me/home/releases/v2.0.5/index.md)   | 2016-09-14 | Fixes a remaining stream end-of-file detection bug in the parser. All changes are backward-compatible.                                                                                                                                                                |
| [v2.0.4](https://json.nlohmann.me/home/releases/v2.0.4/index.md)   | 2016-09-11 | Fixes stream end-of-file detection in the parser. All changes are backward-compatible.                                                                                                                                                                                |
| [v2.0.3](https://json.nlohmann.me/home/releases/v2.0.3/index.md)   | 2016-08-31 | Generalizes the parser to accept any contiguous sequence of one-byte elements and deprecates the input-stream constructor in favor of the [`parse`](https://json.nlohmann.me/api/basic_json/parse/index.md) function. All changes are backward-compatible.            |
| [v2.0.2](https://json.nlohmann.me/home/releases/v2.0.2/index.md)   | 2016-07-31 | Overhauls the parser (now rejecting unescaped control characters), tightens the class invariants, and cleans up the code. All changes are backward-compatible.                                                                                                        |
| [v2.0.1](https://json.nlohmann.me/home/releases/v2.0.1/index.md)   | 2016-06-28 | Fixes a performance regression in the [`dump`](https://json.nlohmann.me/api/basic_json/dump/index.md) function by adjusting the stream locale once per serialization. All changes are backward-compatible.                                                            |
| [v2.0.0](https://json.nlohmann.me/home/releases/v2.0.0/index.md)   | 2016-06-24 | Feature release with a minor (potentially non-backward-compatible) API change from added `noexcept` and `constexpr` specifiers.                                                                                                                                       |

## Version 1.1.x

| Release                                                          | Date       | Summary                                                           |
| ---------------------------------------------------------------- | ---------- | ----------------------------------------------------------------- |
| [v1.1.0](https://json.nlohmann.me/home/releases/v1.1.0/index.md) | 2016-01-24 | Bug-fix and feature release. All changes are backward-compatible. |

## Version 1.0.x

| Release                                                          | Date       | Summary                 |
| ---------------------------------------------------------------- | ---------- | ----------------------- |
| [v1.0.0](https://json.nlohmann.me/home/releases/v1.0.0/index.md) | 2015-12-28 | First official release. |

## See also

- [Migration Guide](https://json.nlohmann.me/integration/migration_guide/index.md) — how to future-proof your code for the next major version and replace deprecated functions.